Northwest gardeners have discovered it’s easy to love a
Hebe, and growers have responded by offering more and more kinds. For a Hebe
enthusiast, each trip to the garden center uncovers new pots of temptation. So
many Hebes, so little garden space!
The number-one reason gardeners give for their
attraction
to these small, flowering shrubs is that “they look so tidy, so neat!” It is
true that in the broadleaf types, the leaves are arranged symmetrically and
often look as if someone had carefully stacked them in four rows up each stem.
The number two reason gardeners love them is for their spikes of purple, pink,
blue and white flowers, so like those of Veronica – exactly what they were
called long ago. When the taxonomists decided they weren’t really Veronicas,
they were named after the Greek goddess of youth, Hebe.
More than 100 species of Hebe
have been discovered in New
Zealand and islands thereabouts, with a couple coming from Chile. While most of
the plants we yearn after belong to the broadleaf Hebes, another group, the
whipcord Hebes, is also intensely interesting.
If you have seen a little mound called
Hebe cupressoides
‘Boughton Dome’ which looks so tight and firm you might assume you could sit on
it, then you know what the whipcord Hebes are. Their small leaves overlap
closely along the stems so they look much like a dwarf conifer. While many of
them bloom, the texture of their foliage is their chief charm.
With all these species
– excellent in their own right –
to work with, plant breeders have hybridized some terrific plants. There are
Hebes for the perennial garden, for the shrub border, for formal gardens, rock
gardens, oriental gardens and more. There are green leaved Hebes, grey leaved
ones, and whipcord Hebes. Each seems to have its own style, so let’s look at
the different kinds.
There are two green-leaved
Hebes that have been around
for many years in the Northwest. Hebe buxifolia, or Box-leaf Hebe, has been
widely used as a quick-growing substitute for Boxwood hedging, as it grows to
three or four feet tall. It is a clean, bright green, and when its little white
bloom spikes open in June and July, it couldn’t be prettier. It should be
trimmed after the blooms fade to stay compact. If it gets leggy, it can be
pruned back by half, as it will fill back in readily.
Hebe mckeanii looks much like
a compact Heather, and is
used in similar positions. Its leaf color is chartreuse-green, and its texture
stays perfect without trimming, at 12 inches tall, spreading to 24 inches. This
one is good to drape over rocks and has little white flowers in summer.
Green-leaved
hybrid Hebes, which may have rounded, shiny
leaves or larger, narrow leaves, have the biggest blooms. They range in height
from about 18 inches (‘Blue Elf’) through four feet (‘Great Orme’). In-between
you will find the purple-flushed foliage of ‘Tricolor’, ‘Amy’, ‘Alicia Amherst’
and ‘Coed’, at about 30 inches. ‘Autumn Glory’, ‘Patty’s Purple’, ‘Variegata’
and ‘Purple Picture’ are about the same height. A little taller are ‘Midsummer
Beauty’ and ‘Nicola’s Blush.’
‘Nicola’s Blush’
and ‘Great Orme’ have pink blooms that
fade to white, creating a pretty two-tone effect. These Hebes all should be
trimmed back after blooming (up to one-third of their height) in order to keep
them thick. It will also bring a second bloom in some, notably ‘Autumn Glory’,
and ‘Blue Elf’. Hebe anomela has red stems and a reddish color in the young,
narrow leaves. It has a fine, dense texture and summer blooms of pale lilac
fading white.
The grey-leaved Hebes tend to be shorter. They are often
from mountainous areas of the South Island of New Zealand. The tried-and-true
Hebe pinguifolia ‘Pagei,’ a small-leaved, six-inch sprawler that roots as it
goes, makes a great groundcover for a well-drained spot in sun. H. pinguifolia
‘Sutherlandii’ is more compact, grey-green, and about 10–15 inches tall by
three feet wide. Both have white summer flowers, but the anthers on
‘Sutherlandii’ are blue, giving it a misty look. H. glaucophylla at 12 to 15
inches tall also will sprawl and
root as it goes, but may be kept bushy by trimming after it blooms. H.
pimeleoides ‘Quick Silver’ is erect and fountain-shaped, needing annual
pinching to keep it full. All these grey-leaved Hebes are extremely useful for
open situations where it is hard to water. They look good with rocks and under
red Barberries.
Hebe ‘Red Edge’ has a blue-green leaf with a thin red
outline that lends interest to mixed container plantings. It has compact growth
to about 18 inches and has lilac summer blooms that fade white. The red edge
looks especially bright in winter. Tiny grey leaves are found on Hebe topiaria,
a chunky mound of about 24 inches. Its small white blooms nearly cover the
leaves in summer, making a dainty picture. Looking very similar, only with a
larger grey leaf, is H. albicans, which is one that rarely needs trimming.
Despite its larger leaf, it does not get quite as tall as H. topiaria, and
looks choice cascading out of a container.
Locally available whipcord Hebes include
the previously
mentioned H. cupressoides ‘Boughton Dome,’ and H. cupressoides itself, which,
just as the name implies, has cypress-like foliage. It blooms with a lilac
flower that fades to white. The attractive golden foliage of H. ochracea ‘James
Stirling,’ is quite hardy (Z 6). It rarely blooms and should not be trimmed.
The whipcord Hebes are wonderful texture accents.
Corinne Kennedy, the enthusiastic
Hebe maven at Magnolia
Garden Center in Seattle’s Magnolia neighborhood, observes that Hebes appeal to
a wide range of gardeners because of their many leaf shapes and colors and
their widely varying growth habits. They are evergreen, many of them flower in
summer, and they are small, making them extremely useful in smaller gardens.
Corinne
notes that they are very popular in containers
and baskets because of their distinctive textures. She says ‘Red Edge’ sold out
continually last summer for that reason. Vashon Island grower, Carole Lynn Ives
of Robinwood Nursery, provides local garden centers with four-inch pots of
Hebes early in the season because they grow so fast, and because the small pots
can be easily tucked into containers with other perennials and annuals to make
fascinating vignettes.
The use and care of Hebes is complicated by conflicting
reports of size and hardiness between English and Northwest growers. Grace
Dinsdale of Blooming Nursery in Oregon, who has been growing Hebes for at least
a dozen years, says that her best efforts have not made the Hebes in her garden
as large as the same ones she sees in English gardens. And some that are rated
more tender in England are considered hardier here. Local growers are trying to
sort out which ones are best for our climate by trial. But it appears certain
that Hebes are not so much cold-sensitive as they are drainage sensitive. In
particular, the whipcord and grey-leaved Hebes, which are mostly mountain
plants, need good drainage. All Hebes need a site in which water never stands,
even in rainy weather. If you have glacial moraine soil, enrich it with compost
and you will find your Hebes thriving!
Some references tell us that Hebes will do well
in sun or
shade, but experience shows that here in Puget Sound they need at least five
hours of sun during the day. The best blooming always occurs with more sun.
Give fertilizer during the spring and early summer (growers like to use
slow-release fertilizer). After blooming, the plants should have the old flower
spikes sheared off, and if the plant is showing signs of legginess, up to a
third of the stem should be cut off. In particular, the green-leaved,
large-flowered types will look much better with this treatment. They will
sprout new twigs, and it is the new twigs that have that attractive neatness.
In addition,
the green-leaved Hebes with larger flower
spikes need shelter from north winds. Most of them are considered USDA Zone
eight plants. But we have only a few short years of experience with some of
these, and there are sure to be revisions. As an example, several growers
mentioned that the beautiful pink flowered Hebe ‘Great Orme’ is supposed to be
hardy to Zone five, but they have doubts, based on the large leaf size, and are
anxious to put it through a really cold winter. One place to shelter Hebes is
at the foot of taller shrubs in a south-facing border. Larger Hebes make good
foundation shrubs on a south or west wall. Unlike Rhododendrons and Azaleas,
they don’t mind the lime that leaches from concrete foundations; they are fine
with either acid or alkaline soils as long as it is not too extreme. Sites like
these examples will give them both shelter and sun.
In the meantime, as committed gardeners,
we must forge
ahead with our Hebe experiments. A new group of Hebes is becoming available,
called the Wiri Hybrids (‘Wiri Mist,’ ‘Wiri Joy’ etc.) which are extremely
floriferous. I can hardly wait!
