Hebe Landscape Evaluation

The landscape evaluation of Hebe at the North Willamette Research and Extension Center (NWREC) was established in 2000 and was removed in 2009. The purpose of the planting was to compare performance of a range of Hebe species and cultivars under typical western Oregon conditions and gather information on their landscape performance. One of the main goals of this trial was to develop comparative data on hardiness of Hebe cultivars and species and identify cultivars that were capable of tolerating typical cold events in a Pacific Northwest winter. In addition to assessing hardiness, other goals were to record flowering and growth information on the various cultivars and species, and also any pest or disease problems.


Plot of Hebe Plants

The first 48 selections of Hebe were planted in 2000. Over the following 4 years, plants were received from cooperators, usually as unrooted cuttings. These were rooted, grown on to 4” or 1 gallon-sized plants, and added to the evaluation each April. In 2001, 88 selections were added to the planting, and in 2002, an additional 45 were added. In 2003, 80 were added, and a final 33 selections were planted in 2004. Primarily because of plant losses to cold and to some extent disease, the evaluation consisted of 201 clones in November, 2006.

Hebe Cuttings Potted Hebe Plants

The planting consisted of a 0.4-acre plot, with 16 double rows, with individual plants spaced at 3’ by 3’ within each double row. Three plants of each clone were planted to allow statistical evaluation of data, although because of the sequential planting over several years, the plants are not randomly distributed in the evaluation, but planted in groups of three. Planting occurred once per year, in April or May, to allow for good plant establishment before winter. Following planting, each row was mulched with bark dust.

Hebe Plants Planting Hebes

Each established plant was fertilized with 2 tbs of 13-13-13, while each new plant received ½ tbs of the same fertilizer. A 5’ wide grass strip separated each row for access. A micro sprinkler irrigation system was installed with the assistance of a grant from the Hardy Plant Society of Oregon.

Meteorological data, including daily maximum and minimum temperature, rainfall and wind speed, are available from the US Bureau of Reclamation Agrimet weather station installed in 1998, located immediately adjacent to the plot. http://www.usbr.gov/pn/agrimet/

Hebe Plot Weather Instrument at Hebe Plot

Plants came from a variety of sources in the western United States and Canada, including nurseries in Oregon, the University of California (Santa Cruz) Arboretum, Strybing Arboretum in San Francisco, Washington Park Arboretum in Seattle and the University of British Columbia Botanical Garden in Vancouver, B.C. However, the majority of the collection was provided by cooperators the New Zealand and the United Kingdom, including Lincoln Botanical, Landcare Research and Christchurch Botanic Garden (New Zealand) and individuals within The Hebe Society (U.K.).

Data Collection

Plant size was recorded at planting time and again in October at the end of the growing season. Plant size was recorded by measuring the height, and two width measurements at right angles to one another, allowing a plant size index to be calculated.

Measuring Hebes

Data on flowering was collected once per month throughout the year, as flowering on various selections continues almost year-round. Flowering information included a rating of flowers on a 0-5 scale. Cold hardiness information was collected following cold events and again in early April. Plants were rated for damage on a 0-5 scale, with 0 indicating no damage and 5 indicating plant death. Intermediate ratings indicate varying levels of damage to leaves and shoot dieback. Information on insect pests and disease problems was collected on a casual basis. The main disease problems proved to be Phytophthora root rot; leaf spot, caused by Septoria exotica, and downy mildew, caused by Peronospora grisea. See Pests and Diseases for more information. A more recent evaluation involves assessing foliage quality and form of the plants, again on a 0-5 scale. The goal was to give some indication of the appearance of the plant in general.

Return to Top

Cold hardiness of Hebe cultivars and species

In New Zealand, Hebe species can be found growing in a wide range of habitats, from sea level to alpine regions, so it is no surprise that cold hardiness of the species, and the cultivars derived from them, varies widely as well. There is truth to the old saying that hardiness of Hebe is related to leaf size. As one goes up in elevation from sea level to alpine areas in New Zealand, the leaf size of the Hebes tends to decrease, and overall plant size decreases as well (Kristensen, 1989). Other characteristics like coriaceous and/or glacous leaves and white flowers are also typical of alpine Hebe species (Wardle, 1978). So, generally speaking, you could say that the larger the leaf of the Hebe, the less cold hardy it tends to be. As with all living things, the rule is not perfect, but the most tender Hebes are usually the largest-leaved, and the hardiest are those with the smallest leaves.

The most extensive study of cold hardiness of Hebe was undertaken by Warrington and Southward (1995), who assessed summer and winter hardiness of 35 species and cultivars. This study showed that large differences in hardiness existed among the various selections. Not surprisingly, the hardiest of those tested were two whipcords, H. cupressoides and H. propinqua, both of which are typically found in alpine or subalpine regions and have very tiny leaves. More important than altitude however, this study observed significant differences in hardiness of species from northern or southern parts of New Zealand, with species of southern origin exhibiting greater overall hardiness.

Some of the research on hardiness of Hebe has utilized excised shoots as sample material for laboratory studies. Bannister (1986) found that detached shoots of Hebe albicans, a South Island species often found in subalpine scrub above 1000m, withstood mid-winter temperatures of -10°C, one of the hardier of the native species studied. Other Hebe species were not tested. In a more extensive study, Bannister (1990) found that mid-winter freezing resistance of foliage of H. buchananii, a diminutive shrub of alpine areas in Canterbury, was as low as -11°C. Freezing resistance of foliage of H. rakaiensis and H. salicifolia, both of which are found at lower elevations on the South Island, was found to be -5.2°C and -6°C respectively. Buds of H. rakaiensis were found to be hardy to -11°C, significantly hardier than leaves. Testing of both H. speciosa, a tender species from seacoast areas of the North Island, and H. odora, a widely distributed shrub of subalpine scrub, found early-winter hardiness of -6°C and -9°C, respectively. Sakai and Wardle (1978) tested excised stems of a wide variety of New Zealand trees and shrubs in mid-winter for hardiness. H. brachysiphon was rated as one of the hardiest species tested, having leaf and bud hardiness of -10°C and -13°C, respectively.

Probably the most extensive anecdotal evidence for hardiness of a wide range of Hebe species and cultivars is provided by Trees and Shrubs hardy in the British Isles (Bean and Clarke, 1991). This monumental work, in 5 volumes, lists descriptions and basic hardiness information on over 100 Hebe species and cultivars. The most extensive field trial of Hebes which included cold hardiness results was the trial of RHS Garden Wisley between 1980 and 1982. In addition to selecting 33 cultivars or species for awards, the trial also indicated which of the trialed plants failed to survive the winter of 1981. Harris and Decourtye (1995) evaluated cold hardiness of many New Zealand plants in field trials over several years in Angers, France. This trial indicated that H. dieffenbachii was tolerant of prolonged cold weather with temperatures as low as -12°C. H. pauciramosa, H. pinguifolia and H. amplexicaulis showed some foliar damage from these conditions. Later data from this trial (Harris et al. 2000) showed that H. albicans and H. subalpina were not injured or suffered only slight injury from prolonged winter cold snaps with temperatures as low as -15°C.

In North America, Hebes are grown primarily as a landscape plant. Because of the intolerance of most Hebes for excessively hot or cold weather, cultivation of Hebes in North America is almost entirely limited to west of the Cascade or Sierra Nevada Mountains in California and the Pacific Northwest. Elsewhere in North America, the climate is generally too cold or hot, or both, to allow for outdoor cultivation, although dedicated enthusiasts have been successful with some varieties in many other areas.

Even in the Pacific Northwest, Hebes are sometimes thought of as too tender for general landscape use, a reputation which is primarily the result of experience with a few popular cultivars which are not particularly cold hardy. Plantings of ‘Amy’, ‘Tricolor’ or ‘Patty’s Purple’ have been severely damaged in cold events on a regular basis, which has unfortunately given the entire genus this reputation. The key to growing these tender cultivars is to provide a protected location near a house or nearby plant.

Protected Hebes

Despite this, many other commonly-available Hebe cultivars like ‘Emerald Gem’, H. carnosula, or H. cupressoides ‘Boughton Dome’, never suffer winter damage.

The level of injury to cold will of course vary depending on the temperature experienced. The hardiest Hebes-the whipcord types and other small-leaved plants-have not typically shown any reaction to winter temperatures in western Oregon over the course of this trial. Since 2000, the minimum temperatures have been no lower than 19°F (-7°C). Even tender Hebes will tolerate temperatures of 25°F without showing signs of stress, especially if these temperatures occur in mid-winter. Abnormally cold temperatures in the fall or early spring are often responsible for damage to these plants and that has been the case in this trial.

The mildest form of damage is leaf discoloration at the shoot tips. More severe cold damage will cause browning and leaf loss on shoot tips.

Major cold damage will cause browning of most of the leaves on the canopy, followed by dieback. Sometimes, plants will recover over a 2-3 year period from this damage if subsequent winters are mild. Very severe, sudden cold often turns the entire plant brown and sensitive cultivars do not recover from this damage and require replacement.

Cold DamageWirigem

References

Bannister, P. 1986. Winter frost resistance of leaves of some plants growing in Dunedin, New Zealand, in winter 1985. New Zealand Journal of Botany. 24:505-507.

Bannister, P. 1990. Frost resistance of leaves of some plants growing in Dunedin, New Zealand, in winter 1987 and late autumn 1989. New Zealand Journal of Botany. 28:359-362.

Bean, W.J. and D.L. Clarke. 1991. Trees and shrubs hardy in the British Isles. 5 Volumes. John Murray.

Harris, W., A. Cadic and L. DeCourtye. 2000. The acclimatization and selection of New Zealand plants for ornamental use in Europe. Proceedings of the 19th International Symposium on Improvement of Ornamental Plants. Acta Horticulturae 508:191-196.

Harris, W. and L. Decourtye. 1995. Observations on cold damage to New Zealand plants grown at Angers, France. Horticulture in New Zealand. 6(1):9-19.

Kristensen, L. 1989. The Genus Hebe-A botanical report. Danish research Service for Plant and Soil Science. Report #S-2034.

Sakai, A. and P. Wardle. 1978. Freezing resistance of New Zealand trees and shrubs. New Zealand Journal of Ecology. 1:51-61.

Wardle, P. 1978. Origin of the New Zealand mountain flora, with special reference to trans-Tasman relationships. New Zealand Journal of Botany. 16:535-550.

Warrington, L.J. and R.C. Southward. 1995. Seasonal frost tolerance of Hebe species and cultivars. New Zealand Journal of Crop and Horticultural Science. 23:437-445.

Return to Top

Cold Hardiness results

Winter temperatures over the course of the trial varied significantly, as might be expected. Temperature data for each period from late October through mid-March, from 2000-2006, are shown in the graphs below. Generally speaking, only temperatures of 27°F or below are of significance, as in this trial, even the most tender Hebe seemed not to suffer injury above this temperature, regardless of when it occurred. More than the actual minimum temperature, the date on which a low temperature was recorded has had the most profound impact on Hebe survival and damage at this site.

The most serious cold damage which occurred during the evaluation followed cold temperatures in early November, 2002, when temperatures dropped suddenly to 22°F. This was a particularly early freeze that caught many Hebes growing and in full bloom, and did extensive damage to many selections, some of which failed to recover. A similar, though less severe freeze, occurred on November 1, 2003, when the temperature again dropped quickly from mild lows to 24.6°F. Again, because of the relatively severe temperature early in the winter, significant damage was done to a wide range of plants. Another early freeze occurred in the first winter of the trial, when the temperature dropped to 23°F on November 18th. The fourth severe freezing event occurred in mid-February, 2006, when the temperature dropped to 20°F on February 20. Much like the early November freezes, this was an uncharacteristically low temperature for the time of year, and occurred following a period of relatively mild temperatures. By late February, many plants, including Hebes, are beginning to grow, and are more susceptible to cold injury. These four events accounted for virtually all of the observable damage to Hebes over the duration of this trial.

In contrast to the injury caused by these early, or late, freezes, similar temperatures in mid-winter have caused no identifiable damage. Temperatures in the low 20’s°F have occurred in January 2004 (20°F, January 6), January 2005 (23°F, January 5) and December 2005 (19.5°F, December 16). In two of the winters of this evaluation (2001-02 and 2004-05), winter temperatures were so mild that no damage which could be attributed to cold weather could be observed.

The accompanying chart shows cold damage to Hebes in the trial by year.
 

        Cold damage rating by year
Row Pos Planted  Plant Name 00-01 01-02 02-03 03-04 04-05 05-06 AVG
1A 1 2000 Hebe 'Wardiensis' 0.0 . 0.0 0.0 . 0.0 0.0
1A 4 2000 Wiri Image' 0.0 . 3.0 4.3 . 0.0 1.8
1A 7 2000 Nicola's Blush' 0.3 . 3.3 2.3 . 0.0 1.5
1A 10 2000 Mrs. Winder' 0.0 . 2.0 0.0 . 0.0 0.5
1A 13 2000 H. recurva 0.0 . 1.0 0.0 . 0.0 0.3
1A 16 2000 Margret' 0.0 . 0.0 . . . 0.0
1A 19 2000 Purple Picture' 0.0 . 4.0 5.0 . . 3.0
1B 1 2000 Icing Sugar' 0.0 . 2.3 0.0 . 2.0 1.1
1B 4 2000 McKean' 0.0 . 0.0 0.0 . 0.0 0.0
1B 7 2000 H. salicifolia 0.0 . 2.0 0.0 . 0.0 0.5
1B 10 2000 Autumn Glory' 0.0 . 3.3 0.0 . 0.0 0.8
1B 13 2000 H. sp. (bidwillii)='Pattys Purple' 4.0 . 4.3 . . . 4.2
1B 16 2000 H. sp ('Little') 2.0 . 4.0 . . . 3.0
1B 19 2000 H. canterburiensis 2.0 . 4.3 . . . 3.2
2A 1 2000 H. sp ('Powis Castle Blue')='Blue Mist' 0.0 . . . . . 0.0
2A 4 2000 Alicia Amherst' 1.3 . 4.3 3.5 . . 3.0
2A 7 2000 H. anomala 'Purpurea' 0.0 . 0.0 0.0 . 1.3 0.3
2A 10 2000 Amy' 1.6 . 4.0 4.3 . . 3.3
2A 13 2000 H. topiaria 0.0 . 0.0 0.0 . 0.0 0.0
2A 16 2000 Patty's Purple' 2.0 . 4.3 5.0 . . 3.8
2A 19 2000 H. sp (buxifolia) 0.0 . 0.0 . . . 0.0
2B 1 2000 H. sp (NWREC 528) 0.0 . 0.0 0.0 . 1.0 0.3
2B 4 2000 Alameda' 0.0 . 1.0 2.0 . 0.0 0.8
2B 7 2000 H. carnosula 0.0 . 0.0 0.0 . 0.0 0.0
2B 10 2000 Oswego' 0.0 . 0.6 0.0 . 0.0 0.2
2B 13 2000 H. cupressoides 'Boughton Dome' 0.0 . 0.0 0.0 . 0.0 0.0
2B 16 2000 H. 'Silver Queen' 3.6 . 5.0 . . . 4.3
2B 19 2000 H. speciosa 1.6 . 4.3 . . . 3.0
3A 1 2000 Heliohebe 'Hagley Park' 0.0 . 2.6 0.0 . 0.0 0.7
3A 4 2000 H. sp ('Prince') 3.0 . 5.0 5.0 . . 4.3
3A 7 2000 H. sp. (haastii) 0.0 . 0.0 0.0 . . 0.0
3A 10 2000 Great Orme' 2.0 . 4.6 5.0 . 3.0 3.7
3A 13 2000 H. pinguifolia 'Pagei' 0.0 . 2.0 0.0 . 0.0 0.5
3A 16 2000 Emerald Gem' 0.0 . 0.0 0.0 . 0.0 0.0
3A 19 2000 Youngii' 0.0 . 0.0 0.0 . 0.0 0.0
3A 22 2000 Wiri Charm' 0.0 . 3.6 2.0 . 4.0 2.4
3A 25 2000 H. speciosa 'Tricolor' 5.0 . . . . . 5.0
3A 28 2000 H. sp. ('Cottage Red Edge') 2.0 . . . . . 2.0
3A 31 2001 H. elliptica . . 5.0   . . 5.0
3B 1 2000 Paula' 1.0 . 5.0 . . . 3.0
3B 4 2000 Jane Holden' 1.0 . 4.0 2.5 . 1.0 2.1
3B 7 2000 Caledonia' 0.0 . 3.0 1.6 . 0.0 1.2
3B 10 2000 H. 'Silver Queen' 2.6 . 4.6 . . . 3.6
3B 13 2000 Autumn Glory' 0.0 . 4.0 1.0 . 0.0 1.3
3B 16 2000 H. traversii 0.0 . 4.0 2.3 . 3.3 2.4
3B 19 2000 Heliohebe hulkeana 0.0 . 3.5 3.0 . . 2.2
3B 22 2000 Parahebe olsenii 2.0 . 4.0 . . . 3.0
3B 25 2000 H. speciosa 'Variegata' 2.3 . 5.0 . . . 3.7
3B 28 2000 Purple Queen' 3.0 . . . . . 3.0
3B 31 2001 H. x andersonii 'Andersonii Variegata'   . 5.0 . . . 5.0
4A 1 2001 Sarana'   . 3.0 2.0 . 1.0 2.0
4A 4 2001 Wiri Cloud'   . 2.0 0.0 . 3.0 1.7
4A 7 2001 H. anomala   . 0.0 0.0 . 0.0 0.0
4A 10 2001 La Seduisante' 83.113   . 5.0 . . . 5.0
4A 13 2001 H. speciosa 91.612   . 4.0 3.0 . 2.0 3.0
4A 16 2001 H. corriganii 91.663   . 1.3 1.0 . 1.0 1.1
4B 1 2001 H. odora 'New Zealand Gold'   . 0.0 0.0 . 0.0 0.0
4B 4 2001 H. strictissima   . 2.0 0.0 . 0.6 0.9
4B 7 2001 H. pubescens   . 4.5 . . . 4.5
4B 10 2001 Denise'   . 2.3 2.0 . 0.0 1.4
4B 13 2001 Parahebe 'Snowcap' 94.96   . 2.0 3.6 . . 2.8
4B 16 2001 Janet'   . 4.0 4.0 . 0.5 2.8
5A 1 2001 H. stricta var. macroura   . 4.0 3.5 . 1.0 2.8
5A 4 2001 Cressit'   . 4.5 . . . 4.5
5A 7 2001 H. sp. (Strybing H-2)   . 0.0 0.0 . 0.0 0.0
5A 10 2001 Bracken Hill'   . 0.6 2.0 . 0.0 0.9
5A 13 2001 Sapphire'   . 2.0 0.6 . 0.0 0.9
5A 16 2001 H. albicans 'Snow Cover'   . 1.0 1.3 . 0.0 0.8
5A 19 2001 Sarnia'   . 3.6 0.3 . 0.0 1.3
5A 22 2001 Purple Tips' 89.54   . 5.0 . . . 5.0
5A 25 2001 H. albicans (prostrate form)   . 2.0 2.0 . 0.0 1.3
5A 28 2001 H. obtusata   . 4.0 5.0 . . 4.5
5A 31 2001 H. sp (Strybing H-12)='Autumn Glory'   . 4.0 2.0 . 0.0 2.0
5B 1 2001 H. sp (Strybing H-8)='Andersonii Variegata'   . 5.0 . . . 5.0
5B 4 2001 H. macrocarpa var. brevifolia   . 5.0 . . . 5.0
5B 7 2001 Lindsay White'   . 4.0 3.0 . 0.6 2.5
5B 10 2001 Pink Pearl'   . 5.0 . . . 5.0
5B 13 2001 White Gem'   . 3.0 2.0 . 0.0 1.7
5B 16 2001 Champagne'   . 3.0 2.0 . 2.0 2.3
5B 19 2001 Andersonii Variegata' 83.118   . 5.0 . . . 5.0
5B 22 2001 Hinerua'   . 0.0 0.0 . 0.0 0.0
5B 25 2001 H. traversii 89.5   . 5.0 . . . 5.0
5B 28 2001 H. stricta var. lata   . 3.0 2.0 . 0.0 1.7
5B 31 2001 H. sp. (Strybing H-1)   . 5.0 . . . 5.0
6A 1 2001 Josephine'   . 2.0 0.0 . 0.0 0.7
6A 4 2001 H. macrocarpa v. brevifolia 84.78   . . 0.0 . 0.0 0.0
6A 7 2001 H. sp. (Strybing H-14)   . 1.0 0.0 . 0.0 0.3
6A 10 2001 H. albicans 'Sussex Carpet'   . 2.0 1.3 . 0.0 1.1
6A 13 2001 Eveline'   . 3.0 2.0 . 0.0 1.7
6A 16 2001 H. sp. (Strybing H-16)=H. rigidula   . 2.0 1.3 . 0.0 1.1
6A 19 2001 H. diosmifolia (Strybing H-15)   . 3.0 0.0 . 0.3 1.1
6A 22 2001 H. sp (Strybing H-10)   . 5.0 . . . 5.0
6A 25 2001 H. sp. (Strybing H-9)   . 4.6 3.0 . 2.0 3.2
6A 28 2001 H. salicifolia v. angustissima   . 3.0 3.3 . 1.6 2.6
6A 31 2001 Diana'   . 5.0 . . . 5.0
6B 1 2001 H. parviflora var. angustifolia   . 2.6 1.3 . 2.0 2.0
6B 4 2001 Pink Payne' 88.102   . 4.6 . . . 4.6
6B 7 2001 Beatrice'   . 3.0 2.3 . 1.0 2.1
6B 10 2001 H. vernicosa   . 3.0 4.6 . 1.0 2.9
6B 13 2001 H. macrantha 91.631   . 0.0 0.0 . 0.0 0.0
6B 16 2001 H. amplexicaulis   . 2.3   . 0.0 1.2
6B 19 2001 Blue Gem'   . 5.0 . . . 5.0
6B 22 2001 Lavender Spray'   . 3.3 3.0 . 2.0 2.8
6B 25 2001 Loganioides'   . 2.5 0.0 . 0.0 0.8
6B 28 2001 H. elliptica 'Variegata' (Strybing H-13)   . 5.0 . . . 5.0
6B 31 2001 H. diosmifolia 84.75   . 5.0 . . . 5.0
7A 1 2001 H. sp. (Western Hills)   . 0.3 0.0 . 0.0 0.1
7A 4 2001 Wiri Gem' 94.56   . 5.0 . . . 5.0
7A 7 2001 H. sp. (elliptica x crassifolia)   . . 0.0 . 0.0 0.0
7A 10 2001 Glauca' 89.221   . 0.0 0.0 . 0.0 0.0
7A 13 2001 H. sp. (Strybing H-3)   . 0.0 0.0 . 0.0 0.0
7A 16 2001 Mohawk' (=Purple Pixie)   . 4.0 2.3 . 0.0 2.1
7A 19 2001 La Favorite'   . 0.0 3.0 . 0.0 1.0
7A 22 2001 H. sp. (Strybing H-4)   . 5.0 . . . 5.0
7A 25 2001 H. x lewisii 'Lewisii'   . 5.0 . . . 5.0
7A 28 2001 Inverey'   . 0.0 0.6 . 0.0 0.2
7A 31 2001 Pink Fantasy'   . 3.3 2.0 . 2.0 2.4
7B 1 2001 H. macrocarpa var. latisepala   . 5.0 . . . 5.0
7B 4 2001 Inverey' 89.18   . 1.0 0.6 . 0.0 0.5
7B 7 2001 H. rigidula   . 0.0 0.0 . 0.3 0.1
7B 10 2001 Violet Snow'   . 3.0 2.5 . 0.0 1.8
7B 13 2001 Co-ed'   . 4.6 . . . 4.6
7B 16 2001 H. elliptica   . 4.6 . . . 4.6
7B 19 2001 Oratia Beauty'   . 2.0 2.3 . 0.0 1.4
7B 22 2001 Pewter Dome'   . 1.3 2.0 . 0.0 1.1
7B 25 2001 Hartii' 94.51   . 1.0 . . 5.0 3.0
7B 28 2001 H. sp. (Strybing H-5)   . 4.0 . . . 4.0
7B 31 2001 H. 'Violaceae'   . 4.6 . . . 4.6
8A 1 2001 H. brachysiphon 89.218   . 5.0 0.0 . 0.0 1.7
8A 4 2001 H. macrocarpa var. macrocarpa   . 0.0 . . . 0.0
8A 7 2001 Blue Mist'   . 3.0 2.0 . 0.0 1.7
8A 10 2001 H. pimelioides 'Quicksilver'   . 0.3 0.0 . 0.0 0.1
8A 13 2001 H. albicans 242/99   . 1.0 1.5 . 0.0 0.8
8A 18 2001 H. pinguifolia   . 0.0 0.0 . 0.0 0.0
8A 20 2001 Blue Elf'   . 4.0 3.0 . 3.0 3.3
8A 23 2001 Maori Gem'   . 0.0 0.0 . 0.0 0.0
8A 26 2001 Pascal'   . 1.0 2.0 . 1.0 1.3
8A 29 2001 Wiri Gem'   . 5.0 . . . 5.0
8A 32 2001 Wiri Vision'   . 5.0 . . . 5.0
8B 1 2001 H. speciosa 'Pink'   . 5.0 . . . 5.0
8B 4 2001 H. hectorii var. laingii 94.53   . 0.0 0.0 . 0.0 0.0
8B 7 2001 Violet Snow'   . 5.0 . . . 5.0
8B 10 2001 H. sp. (Halifax Hardy)   . 0.0 0.0 . 0.0 0.0
8B 13 2001 H. subalpina 331-98   . 0.4 1.0 . 0.0 0.5
8B 20 2001 H. 'Tricolor'   . 5.0 . . . 5.0
8B 23 2001 Blue Gem'   . 3.6 4.0 . 0.6 2.7
8B 26 2001 Blue Clouds'   . 3.0 2.3 . 0.0 1.8
8B 29 2001 Wiri Mist'   . 1.6 2.0 . 0.0 1.2
8B 32 2001 (do not record, mix of clones)   . . 0.0   0.0 0.0
9A 1 2001 H. macrocarpa 'Pink'   . 5.0 . . . 5.0
9A 4 2001 Squalida'   . 2.5 3.0 . 0.0 1.8
9A 7 2001 H. sp. (diosmifolia x albicans)   . 2.3 3.0 . 0.0 1.8
9A 10 2001 H. rupicola   . 0.3 0.0 . 0.0 0.1
9A 13 2001 Leonard Cockayne'   . 0.0 0.0 . 0.0 0.0
9A 16 2001 Bowles's Hybrid'   . 4.0 2.0 . 0.0 2.0
9A 19 2002 H. 'Affinis' 89.60   . 5.0 . . . 5.0
9A 22 2002 Pink Paradise (PVR)   . 1.0 2.0 . 2.0 1.7
9A 25 2002 H. sp. 84.86   . 5.0 . . . 5.0
9A 28 2002 H. gibbsii 89.44   . 0.0 0.0 . 0.0 0.0
9A 31 2002 H. sp. (odora var. prostrata)   . 0.0 0.0 . 0.0 0.0
9B 1 2001 Primley Gem'   . 5.0 . . . 5.0
9B 4 2001 H. albicans 83.120   . 1.0 1.3 . 0.0 0.8
9B 7 2001 H. corriganii   . 4.0 4.0 . . 4.0
9B 10 2001 H. carnosula 'Mount Stewart'   . 0.0 0.0 . 0.0 0.0
9B 13 2001 H. gracillima   . 3.3 2.5 . 1.0 2.3
9B 16 2002 MacEwanii' 83.380   . 1.0 2.0 . 0.0 1.0
9B 19 2002 H. sp. (Strybing H-17)   . 3.0 3.5 . 0.0 2.2
9B 22 2002 H. sp. (venustula)   . 1.0 3.6 . 0.0 1.5
9B 25 2002 Wingletye'   . 0.0 0.0 . 0.0 0.0
9B 28 2002 Wiri Spears' 94.61   . 4.3 . . . 4.3
9B 31 2002 H. townsonii 91.747   . 4.6 . . . 4.6
10A 1 2002 Parahebe formosa 90.178   . 2.0 3.0 . 4.0 3.0
10A 4 2002 H. albicans 83.120   . 0.6 0.0 . 0.0 0.2
10A 7 2002 H. divaricata 84.76   . 3.0 0.0 . 0.0 1.0
10A 10 2002 H. venustula 'Sky Blue'   . 0.3 0.0 . 0.0 0.1
10A 13 2002 H. cupressoides 'Nana' 89.23   . 0.0 0.0 . 0.0 0.0
10A 16 2002 H. sp. ('Patty's Purple Variegated')   . 5.0 . . . 5.0
10A 19 2002 H. ochracea 'James Stirling'   . 0.0 0.0 . 0.0 0.0
10A 22 2002 Clear Skies' PVR   . 1.0 0.0 . . 0.5
10A 25 2003 Parahebe 'Snowcap'   . . 3.0 . 2.0 2.5
10A 28 2003 Mary Antoinette'   . . 2.0 . 2.6 2.3
10B 1 2002 H. pauciramosa var. masonae   . 0.0 0.0 . 0.0 0.0
10B 4 2002 Wiri Prince'   . 5.0 . . . 5.0
10B 7 2002 H. sp. (pinguifolia)   . 0.0 . . . 0.0
10B 10 2002 H. salicornioides 89.39   . 0.0 0.0 . 0.0 0.0
10B 13 2002 Snow Wreath'   . 5.0 . . . 5.0
10B 16 2002 H. glaucophylla   . 0.0 0.0 . 0.0 0.0
10B 19 2002 Pimeba'   . 5.0 . . . 5.0
10B 22 2002 Red Edge'   . 0.6 0.0 . . 0.3
10B 25 2002 Wiri Splash'   . 5.0 . . . 5.0
10B 28 2003 Pamela Joy'   . . 5.0 . 3.0 4.0
10B 31 2003 Tapawera'   . . 2.0 . 0.0 1.0
11A 1 2003 Gibby'   . . 0.0 . 0.0 0.0
11A 4 2003 H. pinguifolia 'Sutherlandii'   . . 0.0 . 0.0 0.0
11A 7 2003 Oratia Gala'   . . 0.0 . 0.0 0.0
11A 10 2003 Gnome'   . . 0.0 . 0.0 0.0
11A 13 2003 H. venustula (Mt. Hikurangi)   . . 0.0 . 0.0 0.0
11A 16 2003 H. buxifolia 'Minima'   . . 0.0 . 0.0 0.0
11A 19 2003 Edinensis'   . . 0.0 . 0.0 0.0
11A 22 2003 H. sp. (diosmifolia x townsonii)   . . 5.0 . . 5.0
11A 25 2003 H. diosmifolia 'Prostrata'   . . 5.0 . . 5.0
11A 28 2003 Autumn Snow'   . . 3.3 . 2.0 2.7
11A 31 2003 H. sp. (harperi)   . . 0.0 . 0.0 0.0
11B 1 2003 H. recurva 'Aoira'   . . 2.3 . 3.6 3.0
11B 4 2003 Greensleeves'   . . 0.0 . 0.0 0.0
11B 7 2003 H. 'Karo Golden Esk'   . . 0.0 . 0.0 0.0
11B 10 2003 Jasper'   . . 3.0 . 0.0 1.5
11B 13 2003 Julie Knight'   . . 0.0 . 0.0 0.0
11B 16 2003 H. buchananii 'Fenwickii'   . . 0.0 . . 0.0
11B 19 2003 Christensenii'   . . 0.0 . 0.0 0.0
11B 22 2003 Parahebe linifolia 'Blue Skies'   . . 3.0 . 2.0 2.5
11B 25 2003 H. imbricata   . . 0.0 . 0.0 0.0
11B 28 2003 Snowdrift'   . . 5.0 . . 5.0
12A 1 2003 H. evenosa   . . 4.3 . 0.0 2.2
12A 4 2003 Baby Marie'   . . 0.0 . 3.0 1.5
12A 7 2003 Geoff. Turnbull'   . . 4.3 . 2.5 3.4
12A 10 2003 H. glaucophylla 'Clarence'   . . 0.0 . 0.0 0.0
12A 13 2003 Hanna'   . . 3.0 . 0.0 1.5
12A 16 2003 County Park'   . . 0.0 . 0.0 0.0
12A 19 2003 Parahebe lyallii 'Baby Blue'   . . 2.6 . 2.0 2.3
12A 22 2003 H. acutiflora (Huka Falls)   . . 5.0 . . 5.0
12A 25 2003 Spender's Seedling'   . . 1.0 . 1.0 1.0
12A 28 2003 Wiri Joy'   . . 4.3 . 2.0 3.2
12A 31 2003 Wiri Magic'   . . 5.0 . . 5.0
12B 1 2003 Hidcote'   . . 4.0 . 5.0 4.5
12B 4 2003 H. rigidula   . . 3.0 . 0.0 1.5
12B 7 2003 Mauve Fingers'   . . 5.0 . . 5.0
12B 10 2003 Christabel'   . . 0.0 . 0.0 0.0
12B 13 2003 Karo Golden Esk'   . . 0.0 . 0.0 0.0
12B 16 2003 H. sp. (Ilirilii)   . . 3.0 . 2.6 2.8
12B 19 2003 Veronica Lake'   . . 5.0 . . 5.0
12B 22 2003 Heidi'   . . 2.5 . 2.5 2.5
12B 25 2003 H. pimelioides var. glauca 84.79   . . 0.0 . 0.0 0.0
12B 28 2003 H. glaucophylla 'Korbel Pewter'   . . 0.0 . 0.0 0.0
12B 31 2003 Lindsayii'   . . 0.0 . 2.0 1.0
13A 1 2003 H. decumbens   . . 3.0 . 0.0 1.5
13A 4 2003 Oratia Beauty'   . . 3.0 . 0.0 1.5
13A 7 2003 Pinocchio'   . . 5.0 . . 5.0
13A 10 2003 Midsummer Beauty'   . . 5.0 . . 5.0
13A 13 2003 H. odora 'Baby Blush'   . . 0.0 . 0.0 0.0
13A 16 2003 H. topiaria 'Rosewarne'   . . 0.0 . 0.0 0.0
13A 19 2003 H. pubescens 90.486   . . 5.0 . . 5.0
13A 22 2003 H. rakaiensis   . . 0.0 . 0.0 0.0
13A 25 2003 Hobby'   . . 5.0 . . 5.0
13A 28 2003 Nantyderry'   . . 0.0 . 0.0 0.0
13B 1 2003 B'limit'   . . 4.0 . . 4.0
13B 4 2003 Wiri Image'   . . 3.0 . 0.6 1.8
13B 7 2003 Champagne'   . . 2.0 . 2.0 2.0
13B 10 2003 Bridget'   . . 5.0 . . 5.0
13B 13 2003 H. parviflora 'Holdsworth'   . . 0.0 . 0.3 0.2
13B 16 2003 Parahebe catarractae 'Porlock Purple'   . . 2.3 . 2.0 2.2
13B 19 2003 Silver Dollar'   . . 0.0 . 0.0 0.0
13B 22 2003 Ettrick Shepherd'   . . 2.6 . 0.3 1.5
13B 25 2003 Gauntlettii'   . . 3.3 . 2.6 3.0
13B 28 2003 Wiri Dawn'   . . . . 2.0 2.0
13B 31 2003 La Favorite' 89.26   . . 5.0 . . 5.0
14A 1 2003 Otari Delight'   . . 4.6 . 3.0 3.8
14A 4 2003 Wiri Grace'   . . 3.0 . 1.5 2.3
14A 7 2003 Gloriosa'   . . 5.0 . . 5.0
14A 10 2003 Dobbies Delight'   . . 5.0 . . 5.0
14A 13 2003 H. albicans (Gouland Downs)   . . 0.0 . 0.0 0.0
14A 15 2003 H. dieffenbachii   . . 0.0 . 2.0 1.0
14A 17 2004 Marjorie'   . . . . 0.0 0.0
14A 20 2004 Boscawenii'   . . . . 4.6 4.6
14A 23 2004 H. venustula 'Patricia Davies'   . . . . 0.0 0.0
14A 26 2004 White Torrent'   . . . . 1.3 1.3
14A 29 2004 Rosie'   . . . . 1.0 1.0
14A 32 2004 Island Pass'   . . . . 0.0 0.0
14B 1 2003 Louise'   . . 5.0 . . 5.0
14B 4 2003 Inspiration'   . . 5.0 . . 5.0
14B 7 2003 H. sp. (procumbens)   . . 2.0 . 0.0 1.0
14B 10 2003 Simon Delaux'   . . 5.0 . . 5.0
14B 13 2003 H. tetragona   . . 0.0 . 0.0 0.0
14B 15 2003 Veronica formosa   . . 2.0 . 0.0 1.0
14B 17 2004 White Heather'   . . . . 1.0 1.0
14B 20 2004 Fairlane'   . . . . 2.3 2.3
14B 23 2004 Dorothy Peach'   . . . . 1.0 1.0
14B 26 2004 Neil's Choice'   . . . . 2.0 2.0
14B 29 2004 Parahebe 'County Park'   . . 0.0 0.0 0.0 0.0
15A 1 2004 Purple Emperor'   . . . . 1.3 1.3
15A 4 2004 Joan Lewis'   . . . . 0.0 0.0
15A 7 2004 Purple Shamrock'   . . . . 2.0 2.0
15A 10 2004 H. elliptica 'Charleston'   . . . . 3.3 3.3
15A 13 2004 Joanna'   . . . . 1.0 1.0
15A 16 2004 Petra's Pink'   . . . . 2.0 2.0
15A 19 2004 Hinderwell'   . . . . 3.0 3.0
15A 22 2004 Hielan Lassie'   . . . . 0.6 0.6
15A 25 2004 Walter Buccleaugh'   . . 0.0 0.0 0.0 0.0
15A 28 2004 Edington'   . . . . 1.0 1.0
15A 31 2004 Headfortii'   . . . . 3.0 3.0
15B 1 2004 Jack's Surprise'   . . . . 3.0 3.0
15B 4 2004 Highdownensis'   . . . . 1.3 1.3
15B 7 2004 Fragrant Jewel'   . . . . 1.0 1.0
15B 10 2004 H. recurva 'Boughton Silver'   . . . . 1.5 1.5
15B 13 2004 Trixie'   . . . . 0.0 0.0
15B 16 2004 Cranleighensis'   . . . . 2.0 2.0
15B 19 2004 Mystery Red'   . . . . 0.5 0.5
15B 22 2004 Monica'   . . . . 0.0 0.0
15B 25 2004 Polden Hills'   . . . . 3.6 3.6
15B 28 2004 Bicolor Wand'   . . . . 1.0 1.0
15B 31 2004 Lavender Lace'   . . . . 3.0 3.0


Note that the names of the plants appear in the chart as they were received. Some of these names are invalid or were incorrect when the variety was obtained and have since been corrected. Others were assigned to distinguish unidentified varieties obtained from a source. Contact the author for information about the identity of individual plants.

Flowering

Flowering times of the Hebes in this trial were assessed monthly. Newly-planted Hebes are not assessed in the year of planting to allow for establishment. Flowering was rated on a 0-5 scale, with 0 meaning no flowers present and a rating of 5 given to those plants which are completely covered with blooms. The following chart shows flowering of the various clones in the trial. In many cases, flower data collection has been interrupted, or stopped, by cold weather affecting the plants.

  Flowering Times  
Plant Name Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Comments
528         XXX                
Alameda'         XXX XXX              
albicans (prostrate form)           XXX              
Alicia Amherst             XXX XXX XXX XXX XXX    
Amy           XXX XXX XXX XXX XXX XXX XXX  
Andersonii Variegata XXX           XXX XXX XXX XXX XXX XXX  
Anomala 'Purpurea'         XXX XXX              
Autumn Glory'           XXX XXX            
Autumn Snow'       XXX XXX XXX              
Baby Marie'       XXX XXX                
Beatrice             XXX            
Bicolor Wand'           XXX XXX            
Bishopiana Champagne             XXX           Tends to rebloom in Sept-Dec
B'limit'                         No data
Blue Cloud           XXX XXX            
Blue Elf           XXX              
Blue Gem           XXX              
Blue Mist           XXX              
Boscawenii                         No data
boughton dome                         Has no flowered
Bowles Hybrid           XXX   XXX XXX XXX      
Bracken Hill           XXX       XXX      
Bridget'                         No data
buxifolia           XXX              
caledonia           XXX              
canterburiensis                         No data
carnulosa         XXX               Blooms only after 4-5 years
Christabel'                         Has not bloomed
Christensenii'                         Has not bloomed
Clear Skies'           XXX             Data affected by Phytophthora problem
Coed           XXX              
County Park'                         No data
Cranleighensis'           XXX     XXX XXX      
Cressit                         Data affected by Phytophthora problem
Denise           XXX       XXX      
Diana             XXX            
Dobbies Delight                         No data
Dorothy Peach'             XXX            
Edinensis                         Has not flowered
Edington           XXX     XXX        
elliptica                         No data
emerald gem                         Has not flowered
Ettrick Shepherd           XXX              
Eveline           XXX              
Fairlane'           XXX             modest in bloom
Fragrant Jewel'           XXX              
franciscana variegata           XXX              
Gauntlettii'           XXX              
Gibby         XXX                
Glauca             XXX XXX          
Gloriosa'               XXX XXX XXX     Data incomplete because of cold damage
Gnome'                         Has not flowered
Goeff. Turnbull'         XXX               winter injury affects results
great orme             XXX XXX         reblooms sporadically through October
Greensleeves'         XXX                
H. 'Affinis' 89.60                         No data-winter killed
H. acutiflora (Huka Falls)                   XXX     Data incomplete because of cold damage
H. albicans         XXX XXX XXX     XXX      
H. albicans (Gouland Downs)           XXX              
H. albicans 242-99           XXX              
H. albicans 83.120         XXX XXX     XXX        
H. amplexicaulis   nbsp;     XXX               Not a strong bloomer
H. anomala         XXX               Not a strong bloomer
H. brachysiphon         XXX XXX             Sporadic rebloom in Fall and Winter
H. buchananii 'Fenwickii'                         Data affected by plant dieback
H. buxifolia 'Minima'         XXX                
H. corriganii       XXX           XXX      
H. corriganii 91.663 XXX     XXX XXX             XXX  
H. cupressoides 'Nana' 89.23                         Has not flowered
H. decumbens         XXX                
H. dieffenbachii           XXX              
H. diosmifolia (Strybing H-15)           XXX              
H. diosmifolia 84.75                         No data-winter killed
H. diosmifolia 'Prostrata'                         No data-winter killed
H. divaricata 84.76           XXX              
H. elliptica                         No data-winter killed
H. elliptica 'Charleston'         XXX         XXX      
H. elliptica 'Variegata' (Strybing H-13)                         No data-winter killed
H. evenosa                         No data-winter killed
H. gibbsii         XXX                
H. glaucophylla         XXX                
H. glaucophylla 'Clarence'           XXX              
H. glaucophylla 'Korbel Pewter'                         Has not bloomed significantly
H. gracillima           XXX              
H. imbricata                         Has not bloomed
H. 'Karo Golden Esk' (11B)                         Has not bloomed significantly
H. macrantha 91.631         XXX                
H. macrocarpa 'Pink'             XXX XXX XXX XXX XXX XXX Data incomplete because of cold damage
H. macrocarpa v. brevifolia                         Data incomplete because of cold damage
H. macrocarpa v. brevifolia 84.78                         Data incomplete because of cold damage
H. macrocarpa v. macrocarpa XXX XXX XXX XXX                 Data incomplete because of cold damage
H. ochracea 'James Stirling'         XXX               Blooms only after 4-5 years
H. odora 'Baby Blush'         XXX                
H. parviflora 'Holdsworth'                         Has not bloomed
H. parviflora v. angustifolia                         Has not bloomed
H. pauciramosa var. masonae         XXX               Blooms sporadically throughout year
H. pimelioides var. glauca 84.79         XXX                
H. pinguifolia         XXX                
H. pinguifolia 'Sutherlandii'         XXX                
H. pubescens             XXX XXX XXX       Data incomplete because of cold damage
H. pubescens 90.486                 XXX XXX     Data incomplete because of cold damage
H. rakaiensis           XXX              
H. recurva             XXX            
H. recurva 'Aoira'             XXX            
H. recurva 'Boughton Silver'             XXX            
H. rigidula (12B)           XXX              
H. rigidula (7B)         XXX XXX              
H. rupicola                         Has not bloomed
H. salicifolia v. angustissima             XXX   XXX XXX     Blooms sporadically in fall
H. salicornioides 89.39         XXX                
H. 'Silver Queen                         Data incomplete because of cold damage
H. sp. (diosmifolia x albicans)         XXX                
H. sp. (diosmifolia x townsonii)                         Data incomplete because of cold damage
H. sp. (elliptica x crassifolia)                         Data incomplete because of cold damage
H. sp. (Halifax Hardy)         XXX                
H. sp. (harperi)             XXX            
H. sp. (llirilii)       XXX XXX                
H. sp. (odora var. prostrata)         XXX                
H. sp. (pinguifolia)         XXX                
H. sp. (procumbens)                         Has not bloomed
H. sp. (unknown clone)   XXX XXX                   Data incomplete because of cold damage
H. sp. (venustula)           XXX              
H. sp. (Western Hills)           XXX              
H. sp. 84.86               XXX         Data incomplete because of cold damage
H. Speciosa 91.612                         Data incomplete because of cold damage
H. speciosa 'Pink'             XXX XXX XXX XXX XXX XXX Data incomplete because of cold damage
H. speciosa 'Violacea'                 XXX XXX     Data incomplete because of cold damage
H. stricta v. lata             XXX            
H. Stricta v. macroura               XXX XXX XXX      
H. strictissima           XXX              
H. subalpina         XXX                
H. tetragona       XXX XXX                
H. topiaria 'Rosewarne'           XXX             Minimal bloom so far
H. townsonii 91.747                         Data incomplete because of cold damage
H. traversii         XXX XXX             Data incomplete because of cold damage
H. venustula (Mt. Hikurangi)         XXX                
H. venustula 'Patricia Davies'                         Has not bloomed
H. venustula 'Sky Blue'           XXX              
H. vernicosa         XXX                
haastii           XXX              
hagley park           XXX XXX            
Hanna'           XXX              
Hartii           XXX             Data incomplete because of cold damage
Headfortii'         XXX XXX              
Heidi'           XXX   XXX XXX XXX XXX XXX Data incomplete because of cold damage
heliohebe hulkeana         XXX               Data incomplete because plant dieback
Hidcote'             XXX XXX XXX XXX     Data incomplete because of cold damage
Hielan Lassie'           XXX              
Highdownensis'           XXX             Some rebloom in fall
Hinderwell'           XXX XXX   XXX       Data incomplete because of cold damage
Hinerua           XXX             Only blooms after 4-5 years
Hobby'               XXX         Data incomplete because of cold damage
icing sugar           XXX XXX            
Inspiration                         Data incomplete because of cold damage
Inverey           XXX     XXX XXX      
Inverey 89.18           XXX     XXX XXX      
Island Pass'                         Has not bloomed
Jack's Surprise'           XXX XXX   XXX        
jane holden             XXX            
Janet           XXX XXX XXX XXX XXX XXX   May continue to bloom in winter
Jasper'                         Has only insignificant bloom
Joan Lewis'         XXX XXX             Data incomplete because of cold damage
Joanna'           XXX              
Josephine             XXX            
Julie Knight'         XXX                
Karo Golden Esk' 12B                         Has not bloomed
La Favorite         XXX XXX              
La Favorite' 89.26                         Data incomplete because of cold damage
La Seduisante             XXX XXX XXX XXX     Data incomplete because of cold damage
Laingii 94.53                         Has not bloomed
Lavender Lace'       XXX XXX XXX              
Lavender Spray           XXX              
Leonard Cockayne       XXX                  
Lewisii           XXX       XXX     Data incomplete because of cold damage
Lindsayii'         XXX XXX             Not a strong bloomer
Lindsey White         XXX XXX              
little               XXX XXX XXX     Data incomplete because of cold damage
Loganioides                         Has not bloomed
Louise'                         Data incomplete because of cold damage
MacEwanii 83.380           XXX              
Maori Gem                         Has not bloomed
margret           XXX              
Marjorie'           XXX              
Mary Antoinette'           XXX             Data incomplete because of cold damage
Mauve Fingers'                   XXX     Data incomplete because of cold damage
mckean                         Has not bloomed
Midsummer Beauty'                 XXX XXX     Data incomplete because of cold damage
Monica'           XXX XXX            
Mount Stewart                         Sporadically produces a few flowers
mrs winder           XXX             Flowers sporadically in summer and fall
Mystery Red'                         Data incomplete because of cold damage
Nantyderry'         XXX                
Neil's Choice'           XXX XXX   XXX XXX      
New Zealand Gold                         Has not bloomed
nicolas blush           XXX     XXX XXX     Flowers sporadically into December
Obtusata                         Data incomplete because of cold damage
Oratia Beauty'           XXX              
Oratia Gala'           XXX             Will flower sporadically into Fall
oswego           XXX     XXX       Flowers sporadically during Fall
Otari Beauty           XXX             Flowers sporadically during Fall
Otari Delight'                         Data incomplete because of cold damage
pagei       XXX                  
Pamela Joy'         XXX XXX             Data incomplete because of cold damage
Parahebe catarractae 'Porlock Purple'         XXX       XXX XXX      
Parahebe 'County Park'                         Data incomplete because of cold damage
Parahebe formosa 90.178                         Data incomplete
Parahebe lyallii 'Baby Blue'         XXX       XXX XXX      
parahebe olsenii         XXX                
Parahebe 'Snowcap'         XXX   XXX XXX XXX XXX      
Parahebe linifolia 'Blue skies'         XXX     XXX XXX XXX      
Pascal           XXX             Flowers sporadically in Fall
patty's purple         XXX               Flowers sporadically later in summer
H. sp. ('Patty's Purple Variegated')                         Data incomplete because of cold damage
paula                         Data incomplete because of cold damage
Petra's Pink'         XXX                
Pewter Dome           XXX              
Pimeba                         Data affected by plant dieback
Pink Fantasy             XXX           Flowers sporadically throughout Fall
Pink Paradise (PVR) XXX     XXX XXX         XXX XXX XXX  
Pink Payne             XXX XXX XXX XXX XXX XXX  
Pink Pearl             XXX XXX XXX XXX XXX XXX  
Pinocchio'                         Data incomplete because of cold damage
Polden Hills'           XXX XXX            
powis castle blue           XXX XXX           Data incomplete because of cold damage
Primley Gem           XXX             Data incomplete because of cold damage
prince             XXX           Flowers sporadically throughout Fall
Purple Emperor'           XXX XXX            
purple picture           XXX XXX   XXX XXX XXX    
Purple Pixie         XXX XXX XXX XXX XXX XXX XXX    
purple queen                         Data incomplete because of cold damage
Purple Shamrock'                         Has not bloomed
Purple Tip             XXX XXX         Data incomplete because of cold damage
Quicksilver           XXX             Data affected by Phytophthora problem
Red Edge                         Data incomplete because of cold damage
Rosie'           XXX     XXX XXX      
salicifolia             XXX            
Sapphire           XXX              
Sarana           XXX     XXX XXX      
Sarnia           XXX     XXX XXX XXX   May continue to bloom in winter
Silver Dollar'           XXX             Sparse bloom, prone to reversion
Simon Delaux                 XXX XXX     Data incomplete because of cold damage
Snow wreath                         Data incomplete because of cold damage
Snow Cover           XXX              
Snowdrift'                         Data incomplete because of cold damage
speciosa           XXX XXX XXX XXX XXX     Data incomplete because of cold damage
speciosa variegata                         Data incomplete because of cold damage
Spender's Seedling'             XXX   XXX        
Squalida             XXX            
Strybing H-1           XXX             Data incomplete because of cold damage
Strybing H-10             XXX XXX XXX XXX     Data incomplete because of cold damage
Strybing H-12           XXX     XXX XXX      
Strybing H-14           XXX              
Strybing H-16           XXX              
H. sp. (Strybing H-17)                         Has not bloomed
Strybing H-2                         No significant bloom
Strybing H-3         XXX XXX              
Strybing H-4               XXX         Data incomplete because of cold damage
Strybing H-5             XXX XXX XXX XXX     Data incomplete because of cold damage
Strybing H-8             XXX XXX XXX XXX XXX XXX Data incomplete because of cold damage
Strybing H-9           XXX   XXX XXX        
Sussex Carpet           XXX              
Tapawera'           XXX              
topiaria         XXX               Not a heavy bloomer
traversii         XXX XXX              
tricolor                         Data incomplete because of cold damage
Trixie'         XXX                
H. venustula 'Patricia Davies'                         Has not bloomed
Veronica formosa           XXX              
Veronica Lake'                         Data incomplete because of cold damage
Violet snow           XXX   XXX XXX       Flowers sporadically throughout Fall
Walter Buccleaugh'                         Has not bloomed
wardiensis         XXX                
White Gem           XXX XXX           Flowers sporadically throughout Fall
White Heather'           XXX              
White Torrent'           XXX XXX            
Wingletye'           XXX              
wiri charm           XXX              
wiri cloud         XXX               Not a heavy bloomer
Wiri Dawn'           XXX     XXX       Data incomplete because of cold damage
Wiri Gem           XXX             Data incomplete because of cold damage
Wiri Gem 94.56             XXX           Data incomplete because of cold damage
Wiri Grace'           XXX       XXX XXX    
wiri image           XXX              
Wiri Image'           XXX              
Wiri Joy'           XXX              
Wiri Magic'                         Data incomplete because of cold damage
Wiri Mist         XXX                
Wiri Prince'                         Data incomplete because of cold damage
Wiri Spears' 94.61                         Data incomplete because of cold damage
Wiri Splash                         Data incomplete because of cold damage
Wiri Vision                         Data incomplete because of cold damage
youngii         XXX XXX              


Note that the names of the plants appear in the chart as they were received. Some of these names are invalid or were incorrect when the variety was obtained and have since been corrected. Others were assigned to distinguish unidentified varieties obtained from a source. Contact the author for information about the identity of individual plants.

Return to Top

Pests and Diseases

Few pest problems were noted in this trial. From time to time, spittlebugs can be seen on the plants in spring, but do no obvious damage.

Hebe Spittle Bug

Earwigs can burrow between the clasped leaves at shoot tips on large-leaved cultivars, and their feeding causes some leaf distortion, but this is sporadic and relatively minor damage.

Earwig Damage in Hebe

Whiteflies may be seen on the plants, but this seems to be rare. Other common pests of landscape plants, like root weevils or aphids, were not observed.

Although they are far from a pest, it should e mentioned that honeybees and other pollinators are very attracted to Hebes. They are to be found on the flowers most times of the year when they are active, but are particularly noticeable in the fall when few other plants are in bloom. Large, fall blooming Hebes will be host to large numbers of honeybees on warm days in late September and October.

Bees in Hebe

Diseases have been more problematic in this trial. The major disease problems have been Septoria leaf spot, Downy mildew and Phytophthora Root Rot. To find out information on management of these diseases in the PNW, see the Pacific Northwest Plant Disease Management Handbook, online at http://plant-disease.ippc.orst.edu/index.cfm.

Septoria leaf spot

This is a fungal disease caused by Septoria exotica. The disease causes small black spots on the leaves, which enlarge and form an ash-colored center. Individual leaves may have large numbers of these spots. The disease is particularly noticeable on large-leaved cultivars, but can be seen on smaller-leaved types as well.

Hebe Septoria leaf spot

The spots become obvious in the late fall and winter on the current seasons growth. The following spring, as the new growth emerges, those affected laves tend to fall off. Over several years, repeated cycles of infection and leaf loss causes a “leggy” appearance to the plant, which can sometimes be temporarily corrected by pruning. Although a formal evaluation has not been done, a wide range of Hebe cultivars seem to be susceptible to the disease.

Downy mildew

This is a fungal disease, caused by Peronospora grisea. The disease causes major leaf damage, leaf loss and shoot dieback, eventually it can cause plant death. The disease is usually noticed first by a yellowish, blotchy discoloration of the leaves, often on the lower leaves of the plants. This discoloration can affect large portions of individual leaves. Leaves become curled and distorted. On the underside of the leaves a grayish sporulation of the fungus may be seen.

Downy Mildew in Hebe

Eventually the affected parts of leaves turn brown and shrivel. Plants can be entirely defoliated and killed.

This disease is a serious problem for cultivation of some Hebes in the landscape in the U.K. In western Oregon, it is generally not a problem for landscape shrubs in the Willamette Valley, assuming they are given sufficient light and air circulation. The only time it seems to occur in this area is if a Hebe is grown in too much shade in a moist environment. On the Oregon Coast, persistent summer fog can induce the problem in nursery or landscape situations.

Root rot

Both Phytophthora sp. and Fusarium oxysporum and been implicated in root rot problems of Hebe. Phytophthora tends to be more of a problem in cold soil, while Fusarium is more common in warm soils. The disease is usually first noticed by the flagging of individual stems, often in mid-summer. Leaves on these stems turn yellow then brown. Entire sections or sides of the shrub may become affected quite rapidly, looking almost as though it were burned.

Red Edge Dieback in Hebe

Plants may be stunted. Roots below affected branches are rotted. The entire plant may die, or it may persist for months in this state. Phytophthora in particular is more likely to be an issue in heavy-textured soil or poorly-drained sites. Amending these soils with organic matter and other amendments will improve soil aeration and reduce the likelihood of disease. Ensure the site is well-drained and water regularly but not to excess. Most established Hebes growing in good soil require water only 1-2 times per week for a few minutes from a typical irrigation system.

Return to Top

Drought tolerance

Hebes are often referred to as “drought-tolerant” shrubs and may be sold by retailers as such. However, even in the Pacific Northwest, summers are warm and dry enough to stress virtually all Hebes if regular summer water is not provided. This is particularly true of summer and fall-blooming cultivars, which bloom on new growth, and require regular water to continue growing, without which they will stop producing flowers.

How Hebes came to be regarded as “drought-tolerant” is a bit of a mystery, unless there is a tendency to associate evergreen plants in general with drought tolerance. The term “drought-tolerant” can mean a lot of different things, but if we use the definition, “a plant which will survive in the PNW entirely on rainfall without added summer irrigation”, then few Hebes will perform well under these conditions. The PNW is a Mediterranean-type climate, with a pronounced dry period of 3-4 months, and summer temperatures will exceed 90°F in the Willamette Valley on 14-21 days each summer. Almost all Hebes are from New Zealand, and therefore originate in a relatively mild, cool climate with at least some summer rainfall.

Kristensen (1989) classified Hebe species as to their origin in wet or dry habitats. About 1/4 of the listed species evolved in dry habitats. This includes familiar species like H. pinguifolia, H. carnosula, H. rakaiensis, H. decumbens, H. pimelioides and H. cupressoides. However, even the “dry” habitats received up to 60cm of rain per year. As a result, most of the available cultivars share this need for at least occasional summer water, depending on conditions. It is almost impossible to say what the water requirement of a particular cultivar will be, because many are of unknown parentage. Instead it will simply have to be planted and evaluated in the conditions characteristic of that site.

Symptoms of drought stress are expressed in a variety of ways. The first signs are typical of most plants and involve drooping of leaves and even shoot tips.

Drought Hebe

This is reversible if water is immediately provided. Repeated events like this will cause the leaf color in many Hebes to change from a glossy green to a pale, dull appearance, particularly on the older leaves.

Drought Hebe

Prolonged stress will cause yellowing of the foliage, and brown, necrotic areas will develop on the leaves, especially on the midrib.

Drought Hebe

The older leaves on the bottom and interior parts of the canopy will start die and fall off, in many cases giving the plant a “leggy” appearance.

Drought Hebe

Continued lack of water will cause dieback of portions of the canopy and eventually the entire plant.

Factors which will determine how much water a given Hebe will require are many:

Cultivar

Some Hebes do survive and grow well with limited water. Although evidence is scant, and based primarily on casual observation, in general blue-leaved Hebes seem to tolerate dryer garden conditions in the PNW than whipcord or large-leaved cultivars. Even these plants will still prefer a good watering every 7-10 days in the warmest part of summer and should not be planted with truly drought-tolerant Mediterranean plants like Ceanothus, Cistus or Rosemary, which are best without summer water.

Site

The site will have a major impact on water requirement. Hebes planted in full sun naturally require more water than those in some shade. Plants on the south or west side of buildings will be particularly stressed from the added heat from the building. If protection from mid- to late-afternoon sun is provided, then water requirement will be reduced. Do not plant in full shade as this will result in poor growth and possibly foliar disease problems.

Soil

Soil is another important factor and all Hebes prefer a well-amended, well-drained soil for best growth. Heavy, compacted soils do not allow for good root growth of fibrous-rooted plants like Hebes and this will increase drought stress. Amendment of these soils with organic matter prior to planting is a good start. Mulching following planting, and avoiding foot traffic on the soil afterward, will help good structure to develop and improve conditions for root growth and water storage in the soil. For more information on soil amendment and mulching, see EC 1561, Improving garden soils with organic matter, or EC 1629-E, Mulching woody ornamentals with organic materials. Both are available from OSU Extension publications: http://extension.oregonstate.edu/catalog/.

Website creator

Neil Bell
Community Horticulturist
OSU Extension Service
Marion and Polk Counties
3180 Center Street NE #1361
Salem, OR 97301
Phone: 503-361-2671
neil.bell@oregonstate.edu
 

References

Kristensen, L. 1989. The Genus Hebe-A botanical report. Danish Research Service for Plant and Soil Science. Report #S-2034.

Books and websites     Return to Top

There are now several excellent texts on Hebes, which are essential for those concerned with correct naming of species and cultivars, as well as being sources of information on culture of these plants:

Bayly, M and A. Kellow. An illustrated guide to New Zealand Hebes. Te Papa Press.

Chalk, D. 1988, Hebes and Parahebes. Timber Press, Portland, OR. 152 pp. (out of print)

Hutchins, G. 1997. Hebes here and there. Hutchins and Davies, Reading, Berks. 320 pp.

Metcalf, L.J. 2001. International Register of Hebe cultivars. Royal New Zealand Institute of Horticulture. 232 pp.

Metcalf, L. 2006. Hebes: a guide to species, hybrids and allied genera. Timber Press, Portland, OR. 260 pp.

Wheeler, Chris and Valerie. 2002. Gardening with Hebes. Guild of Master Craftsman Publications. 160 pp.

Another fundamental source of information on Hebes is The Hebe Society, whose website has a wealth of information and links. http://www.hebesoc.org