If we can judge the
popularity of a gardening endeavor by
the number of books written on it then
the decade of the 90's should be known
as the decade of native plant
gardening, at the very least in a
relative sense. We have 15 books on
native plants or wildflowers that were
published in the 90's, but only 3 from
the 80's, 2 from the 70's and 1 from
the 60's (and with recent publication
of William Cullina's great new book,
The New England Wildflower Society
Guide to Growing and Propagating
Wildflowers of the United States and
Canada, already 1 book in the 00's).
Many of you may have been growing
native plants in your home gardens for
many years. Others might be wondering
what all the fuss is about, and usually
have two questions: What plants can be
considered native and why should I
incorporate them into my garden?
Native plants are
those that grow naturally in a certain
region and were not introduced to that
region by humans. So many
"wildflowers" are not native
plants. For example, purple loosestrife
(Lythrum
salicaria)
grows naturally in our region but was
introduced here from overseas. It has
become a problem plant in wet meadow
habitats, forming virtual monocultures
that crowd out indigenous species. The
same could be said for many of the
plants included in wildflower seed
mixes although most are not quite the
rogue that purple loosestrife has
become.
As you can see from
our definition of native plant, in
order to determine whether a plant is
native or not, a gardener must first
circumscribe the region that he or she
considers their garden to be a part of.
And this is largely subjective and up
to the whim of the individual gardener.
You might decide that you are a
Catskill Mountain gardener or an Ulster
County gardener or a Hudson Valley
gardener or an eastern deciduous forest
gardener. Any of these choices would be
fine. Gardening with native plants
should not be thought of as an
intrusion of political correctness into
the horticultural world, but as an
attempt to develop gardens that possess
a regional identity. Does your shade
garden consist largely of Japanese
pachysandra, hostas and impatiens,
struggling to grow under a Norway maple
and alongside a hedge of forsythia
overtopped with Japanese honeysuckle?
If so, you have plenty of company
around the world. Now suppose the
denizens of your shade garden are wild
ginger (Asarum
canadense),
wood poppy (Stylophorum
diphyllum),
Solomon's seal (Polygonatum biflorum), lady fern (Athyrium filix-femina), sweet white violet (Viola blanda), and Pennsylvania sedge
(Carex
pensylvanica),
growing under the shade of red oak (Quercus rubra) and sweet birch (Betula lenta) with withe-rod (Viburnum cassinoides) and high-bush blueberry
(Vaccinium
corymbosum)
in the understory. Your shade garden is
a microcosm of eastern North America
deciduous forest. And, with the
exception of the wood poppy which has
more of a midwestern and southern
distribution, all the plants in your
shade garden can be found growing
locally.
But how about that
wood poppy? Some might wonder if a
native plant gardener has no qualms
about putting wood poppy into a
Catskill Mountain or Hudson Valley
garden even though the species doesn't
grow wild in these locations, what's so
wrong with growing one of those
wonderful Asian jack-in-the-pulpits
like the Japanese cobra lily (Arisaema sikokianum)? The answer is nothing
is wrong with growing Japanese cobra
lily in your shade garden or a few
hostas. This is an example of
ecological gardening in which the
gardener uses species from around the
world that are adapted to our
environmental conditions. The garden
becomes a composite of native plants
and plants from similar bioregions
around the world, but still retains a
strong regional identity. Obviously the
strength of that identity begins to
wane as the proportion of non-native
species in the garden increases as do
the advantages that come from growing
native plants. At the extreme is the
hosta-Norway maple-forsythia-Japanese
honeysuckle garden that has no native
plants, no regional identity, and none
of the advantages that come from
growing native plants, but does have
certain disadvantages that can arise
from the use of exotic plants in the
garden.
There are five
reasons to incorporate native plants
into your garden.
(1) Aesthetics -
Native plants are ornamental.
Some of the hottest
plants in ornamental horticulture
currently come to us from Asia, where
plant explorers continue to find new
and interesting and occasionally even
spectacular plants, for example the
Japanese cobra lily mentioned above.
Many gardeners find these plants to be
more interesting or beautiful than our
native plants and certainly Asia has a
much more diverse group of
jack-in-the-pulpits than occurs in
eastern North America, where we have
only two members of the genus,
jack-in-the-pulpit, Arisaema tryiphyllum, and the green dragon, Arisaema draconitum. Now we happen to find
our own jack-in-the-pulpit to be as
attractive and interesting as most of
the Asian species and the green dragon
as unusual, but there is a natural
human tendency to value the new and
exotic over the commonplace. But if
it's the new and unusual you're after,
how about Baptisia, a genus of North
American plants that most of you are
probably not familiar with but which
contains at least a half dozen stately
plants with interesting, blemish-free
foliage, pea-shaped flowers that come
in shades of blue, white, or yellow,
and ornamental seed pods. If you're
just looking for beauty and don't mind
commonplace, it's hard to beat Echinacea or Rudbeckia, two uniquely North American
genera whose members include some of
the most popular and beautiful garden
plants. Or, if diversity is you're
thing, North America is home to around
250 species of Penstemon, and virtually every member of
the genus is a wonderful ornamental
with tubular flowers in shades of red,
pink, purple, blue, yellow and white.
We could describe many more great North
American plants but we think you get
the point: the plants of North America
are every bit as garden-worthy and
ornamental as those that hail from
other continents. If you don't believe
me, just check with European gardeners,
whose flower borders rarely go without
such North American plants as
joe-pye-weed (Eupatorium spp.), goatsbeard (Aruncus dioicus) or black cohosh (Actaea racemosa) or European plant
breeders who create cultivars of many
of our native plants, then send them
back over the Atlantic to unsuspecting
gardeners who snap them up, not
realizing that the progenitor of the
cultivar can be found growing wild
nearby and be just as attractive in
their gardens. A perfect example is Helenium - nursery catalogs are
full of cultivars with names such as
Kugelsonne (Sunball) or Dunkelpracht
(Dark Beauty) that were created by
European breeders. They are primarily
derived and in many cases are
indistinguishable, at least to our eye,
from sneezeweed or Helen's flower, Helenium autumnale, a common wet meadow
plant of eastern North America.
(2) Horticulture -
Native plants are adapted to the
conditions we garden in
For beginning
gardeners especially, who may not yet
be as knowledgeable about plant needs
as more experienced gardeners, native
plants take the guesswork out of
gardening and help ensure that one's
first garden doesn't become one's
first, very expensive, compost pile. If
you choose plants that are native to
our region they are likely to thrive in
our warm, wet summers, fluctuating
spring temperatures, cold winters, and,
usually, acidic, clayey, rocky, soils.
After all, these are precisely the
conditions in which the plant grows in
the wild, and without the nurturing
hand of the gardener. Of course,
knowledge of plants still helps. Marsh
marigold (Caltha
palustris),
not a marigold at all, but a member of
the buttercup family, is a common
native plant in our area, but as you
can surmise from its name, inhabits wet
meadows and pondsides and needs
abundant moisture in spring - it will
languish and die in a location that is
sunny and dry throughout the year. The
beginning gardener can't just assume
that because marsh marigold is a native
plant that it will thrive in any garden
location.
Although it seems
to be a common notion, it is not
necessarily the case that native plants
are more unpalatable to the current
scourge of our gardens, the
white-tailed deer, than exotic plants.
For example, there is probably no plant
more reliable deer-resistant than the
daffodil, which hails from Europe and
North Africa, while one of our most
beautiful native plants, the cardinal
flower (Lobelia
cardinalis)
is like candy to deer - if they find it
they will eat it.
(3) Ecology -
Native plants provide habitat and food
for wildlife
Virtually all
plants, native or exotic, provide
nesting areas for birds and small
mammals, and food for them as well -
and food for many different kinds of
insects including butterflies, bees,
and garden beneficials (those insects
such as ladybird beetles and syrphid
flies that help us out by preying on
garden pests such as aphids). However,
native plants are particularly good
choices for those interested in
wildlife gardening because our local
wildlife is often adapted to our local
plant species. This probably applies
less to birds who seem to have no
problem feasting on non-native fruits
such as orchard cherries, than to
insects, many of which are
host-specific. The best regional
example of this occurs in the Pine Bush
habitat near Albany, where native
plants such as wild lupine (Lupinus perennis) and horsemint (Monarda punctata) thrive in the sandy
soil and hot, dry conditions. Much of
the Pine Bush has disappeared under the
combined pressures of housing
developments, shopping malls and
highway construction. Along with the
habitat, of course, go the plants, and
along with the plants goes a
particularly beautiful small butterfly,
the Karner blue - an endangered species
that feeds exclusively on wild lupine.
As a society we can create nature
preserves where lupine and Karner blue
butterflies can persist. However, the
potential amount of habitat for
wildlife that can be created by home
gardeners is immense - imagine the
cumulative effect if every home
gardener devoted at least a portion of
their garden or property to creating
habitat for wildlife. If you live in or
near the Pine Bush of Albany, you can
help preserve the Karner blue
butterfly. If you live somewhere else,
the habitat you create will help
preserve numerous species of birds,
insects, amphibians, reptiles and
mammals even if they are not currently
in as desperate a situation as the
Karner blue.
Another reason that
native plants are a better choice for
wildlife gardening than exotic species
is that most have not been overly bred
for characteristics that humans find
desirable. When plants are bred for
overall size, or for flower color, size
or form, they often lose other features
that make them useful for wildlife.
They may lose the fragrance that
insects use to locate the plants -
think of many of our modern rose
cultivars. Production of nectar or
pollen may be considerably diminished
in cultivars and this makes the plants
less useful for butterflies, bees and
many other insects. Many cultivars are
hybrids and so are often sterile and do
not produce viable seeds. Shrunken,
inviable seeds are of little food value
to birds and many insects that are seed
eaters. As natives become more popular
garden subjects, breeders are beginning
to create "improved"
cultivars and these may suffer from the
same problems as cultivars of exotic
plants. Generally speaking, the best
choices for wildlife gardening are
native plants that have not been
"improved" according to human
standards.
(4) Conservation -
Native plants populations are in
decline
Many native plants
are becoming rarer as we turn
increasing amounts of wild land into
workplaces, housing developments and
shopping malls. Overbrowsing brought
about by out-of -control deer
populations is also responsible for
reducing the sizes of native plant
populations. Home gardeners can help
reverse this trend by growing native
plants. But to ensure that you are
helping to conserve declining native
plant populations you have to be
careful about how you obtain your
plants. Many native plant gardeners may
be doing more harm then good if they
obtain plants by digging them from the
wild or buying them from nurseries that
dig plants from the wild. If you dig
plants from the wild you aren't
increasing plant numbers, but simply
moving plants around in space.
Moreover, many plants that are dug from
the wild do not survive for long in our
gardens. They suffer from transplant
shock or from being put into the wrong
spot. Large, mature specimens are often
the plants that people spot on a stroll
through the woods. They are so
impressive that people decide to move
them to their garden - but large,
mature specimens don't transplant well
and are unlikely to survive. If a
nursery doesn't state that their plants
are nursery propagated assume that they
are not and beware of statements such
as "Our plants are nursery
grown". Plants can be dug, held in
pots for any length of time and be
considered nursery grown. Look for a
statement that the plants are nursery
propagated. Some nurseries claim to be
selling plants that are rescued from
housing or other developments where
they clearly face imminent demise. Be
wary of these nurseries as well,
because there is no law that prevents
such a claim from being made even if it
isn't true. Become more familiar with
the plants you are growing or wish to
grow - their life cycles and the means
by which they can be propagated. Then
rather than digging plants from the
wild or obtaining them from nurseries
that dig plants, propagate your own. We
think you'll find that this will take
your gardening to a new level of
satisfaction.
And if you don't
have the time or resources to propagate
all the plants you would like for your
garden, obtain plants from nurseries
that sell only propagated plants.
The best
opportunity for local gardeners to help
conserve a federally-listed endangered
species involves the wild monkshood (Aconitum noveboracense). This plant has a
disjunct North American distribution,
being found in a few localities in the
midwest and in New York State. In New
York it is found at only a few sites in
the Catskill Mountains. In conjunction
with the Olive Natural Heritage
Society, Catskill Native Nursery is
involved with an effort to conserve the
species. We are propagating monkshood
by seed and hope to eventually
establish new populations at sites in
the Catskills. Eventually, wild
monkshood plants will also be available
for sale at the nursery. But don't get
the idea that only officially
"listed" plants are worthy of
attention. By growing any of our local
native plants in your garden you will
be helping to conserve them.
(5) Conservation -
Exotic plants can be invasive
Many popular exotic
garden plants can escape our gardens,
invade wild lands and reduce
populations of native plants. This
could be a topic for an entire article,
but here I'd like to briefly address
the issue by providing a couple of
examples. At the beginning of this
article we described a hypothetical
shade garden. Two of the plants in that
garden have the potential to be
invasive and probably should be avoided
in any new plantings and perhaps
eliminated from existing gardens.
Japanese honeysuckle (Lonicera japonica), along with a number of
Asian bush honeysuckles, has fragrant
flowers and colorful red berries that
provide food for birds. Birds, of
course, are indiscriminate in where
they deposit the seeds contained in
those berries after they have passed
through their digestive system. By this
mechanism, Japanese honeysuckle moves
out of our gardens and into surrounding
lands. Being adaptable to a wide range
of soil types, moisture regimes, and
light densities, it has no trouble
establishing itself in just about any
habitat. It covers the ground in a
dense thicket that smothers other
plants and can overclimb shrubs,
eventually smothering them. The Norway
maple (Acer
platanoides)
is a popular ornamental tree that is
fast-growing in a variety of soil,
moisture and light conditions, and has
few pests or diseases. It is similar in
size, shape, flower and fruit to our
native sugar maple (Acer saccharum), but generally
outcompetes it when the two grow in the
same area. Mature trees produce
numerous seedlings surrounding the
parent tree, and in combination these
cast a dense shade under which
virtually no other herbaceous plants or
tree seedlings survive. Clearly,
gardeners will be doing native plants a
favor if they avoid growing these
plants in their gardens. Instead of
Norway maple plant sugar maple and
instead of Japanese honeysuckle, plant
our native trumpet honeysuckle (Lonicera sempervirens).
