We are planning a 30′ x 100′ planting bed to screen a metal building
and have been thinking about using a variety of holly for the background evergreen tree in this bed. Do you have any recommendations for varieties that do well in the Puget Sound area and are as pest free as possible, and yet have good color, berries and form. Setting has: sun, good soil, irrigation if needed and no height restrictions.
The local resource, Great Plant Picks, recommends the following hollies:
- Ilex aquifolium ‘Ferox Argentea,’ or hedgehog holly. Note that this clone
does not produce berries, which is considered by some to be a positive
attribute, as berries can lead to nuisance plants sprouting in the
garden. - Ilex crenata ‘Convexa’ (convex-leaf Japanese holly)
- Ilex crenata ‘Mariesii’ (columnar Japanese holly): this is a female clone
whose flowers will develop black berries if pollinated.
Great Plant Picks offers more information and images.
Ilex aquifolium (the species) is now considered an invasive plant in our
area. The Tacoma News Tribune published an article on this topic, with suggested alternatives. Excerpt:
“Just don’t plant English holly (Ilex aquifolium), the species with the
dark, glossy leaves and bright red berries that most people picture when
they hear the word ‘holly.’ This non-native species has become invasive
here and isn’t recommended for home gardens (see box for more
information), so leave it to the professional growers.
But that still gives gardeners about 400 species of holly to choose from,
and many can be seen at the Washington Park Arboretum in Seattle, which
has the second-largest holly collection in the U.S.
‘Our U.S. native Ilex opaca (American holly) and its many cultivars are
underutilized and in many cases better ornamentals than (the) Ilex
aquifolium counterparts,’ said David Zuckerman, horticulture staff
supervisor at the arboretum, which is part of the University of
Washington Botanic Gardens.”
Like American holly, some hollies have the ‘traditional’ holly look,
while other holly species display different charms.
One of Zuckerman’s favorites is the deciduous Ilex verticillata. Although
the plant’s oval leaves drop in the fall, ‘the berries persist through
winter and can really liven up the winterscape,’ he said.
Japanese holly (Ilex crenata) is a family of ‘quite handsome shrubs’ with
small evergreen leaves and black berries, Zuckerman said. These hollies
look more like boxwood than holly, and lend themselves to hedging and
topiary. ‘I really enjoy some of the whimsical dwarf-forms,’ he said,
such as Sky Pencil, which grows 6 to 8 feet tall but just 12 to 18 inches
wide, adding a vertical accent to the landscape.
When adding holly to the garden, remember that hollies are dioecious and
both male and female plants are needed for the female to produce berries,
Zuckerman said. Good companion plants for evergreen hollies include
deciduous choices like witch hazel, lindera (spicebush) and corylus
(filbert), Zuckerman said. And Asian plants such as Japanese maple and
bamboo can partner well with the more formal-looking Japanese hollies, he
said.
I wonder if you might also consider other plants which have colorful
fruit but are less likely to become invasive. This article,
from local website Rainy Side Gardeners, lists a few possibilities, like
Arbutus, Gaultheria, Mahonia, Skimmia, Nandina, and Sarcococca.