University of Vermont Extension
Department of Plant and Soil Science
Anytime News
Article
SUSTAINABLE LANDSCAPE PLANTS
Dr. Leonard Perry, Extension Professor
University of Vermont
Unless you're a specialist plant
collector, you probably choose landscape plants on what is appealing to
you in
flower or foliage, or both. For most,
cost also is a factor. Increasingly
gardeners want landscape plants that are sustainable-- no significant
problems,
not invasive, drought tolerant once established, low maintenance, and
long-lived. To be sustainable, plants
must be matched to their site, or "right plant, right place".
Otherwise plants may grow poorly, need lots
of care, or worse, die off.
So once you find an appealing
landscape plant, consider where it will be planted. A bit more
planning up front pays off with
longer lived, more healthy plants, and much less labor later.
Here are
10 main factors in matching a plant
to its future home, and to your needs and resources, in order for it to
be
sustainable.
--Hardiness. If you don't know what hardiness zone you
live in, get familiar with this (books, online, and store personnel can
help)
and see if it matches your plant choices.
Keep in mind there are small climate variations on most properties--
microclimates-- that can be warmer or colder.
Consider these when finding sites for new plants.
--Height
and width. Find a space of suitable size
for your plants when they are mature.
This will keep you from excessive pruning, or having to relocate them
when large and hard to dig.
--Sun
exposure. Determine if your plant
prefers sun or if shade, how much. And
will it tolerate the opposite?
--Soil
pH. Does your plant need a certain pH or
soil acidity, or will it do well as most do in a slightly acid
soil?
What is your soil pH? If you don't know, inquire at your garden
store about soil testing and kits, or from your local Extension
office.
--Soil
type. Is your soil well-drained? What does your plant need,
or at
least
tolerate? Also consider whether your
plant will tolerate a soil extreme if you have such, like sand or clay.
--Drought. Once the plant is established (water well the
first year after planting), will it tolerate drought? If so this
will
save you on the time and
expense of watering often.
--Growth
habit. This could be thought of in terms
of plant shape, also in terms of its behavior.
If you want a rounded plant, buy one with a rounded shape unless you
want to spend lots of time shearing. Is
the plant "vigorous"? (This is
often a term on labels and in catalogs for aggressive spreaders that
will
overtake a bed and may become invasive even beyond.) If so, do you have
a site
where it can be contained? (Pavement such as walks and walls contain
spreaders
well.)
--Pests
and diseases. Check to make sure your
plant doesn't have serious problems with these, or can tolerate them
(such as
powdery mildew on garden phlox). If it
can tolerate a disease, can you tolerate the looks of it aesthetically?
--Maintenance. This relates more to your own time and
resources. Will your plant require
frequent pruning, fertilizing, deadheading (nipping off) old flowers,
staking,
or similar?
--Longevity. Is your plant long-lived, or will it die out
(such as the biennial hollyhock or short-lived delphinium), or need
digging and
replanting or dividing every couple years (such as some coralbells)?
In addition to considering these
factors for each plant, consider a couple others for your plants to
make your
whole landscape sustainable. Use a
diversity of plant choices, the more the better. This not only
makes a
landscape more interesting,
but helps beneficial insects and pollinators,
and avoids big loses should harmful insects or diseases invade. A
diverse plant palette also will be more
beneficial to wildlife. Choose plants to
provide shelter and food. Many gardeners
start their choices with native plants, but don't overlook others that
may fit
these needs.
For deciduous trees (those that lose
their leaves in winter), consider for smaller trees the crabapples
(look for
disease resistant cultivars), three-flowered maple, Japanese tree
lilac, and
native river birch and American hornbeam.
For large deciduous trees consider the native American hop-hornbeam,
sugar or red maple, American yellowwood, American beech, oaks,
silverbell, and
larch. Large non-native trees include
the ginkgo, katsura tree, and Japanese zelkova. Evergreen trees for
sustainable
landscapes include white pines, spruces, and arborvitae.
For evergreen shrubs, consider the
eastern red cedar or junipers (disease resistant species and
cultivars). Deciduous native shrubs include the
bottlebrush buckeye, fothergilla, red chokeberry, inkberry,
winterberry,
summersweet clethra, sumacs, and highbush blueberry. Deciduous
non-native shrubs include 'Miss
Kim' and 'Palibin' lilacs, as well as shrub dogwoods.
There are many perennials to choose
for sustainability. Some non-natives include
feather reed grass, 'Rozanne' perennial geranium, bigroot geranium,
daylilies,
and sedum. Native perennials include
false indigo, bluestars, 'Moonbeam' coreopsis, coneflowers, joe-pye,
switchgrass, black-eyed susan, little bluestem grass, bugbane, phlox,
and
foamflower.
More choices for sustainable
landscape plants, including ones resistant to some specific major
pests, can be
found in a factsheet by Deborah Swanson from University of
Massachusetts
Extension (www.umassgreeninfo.org/fact_sheets).
Return to
Perry's Perennial
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