PLANTS TO RUN AWAY FROM
This is a rough copy of something I will work more on!
"The greatest service which can be
rendered any country is to add a useful plant to its culture."
Thomas Jefferson.
Some 150 years ago, when American
horticulture was still in its infancy Asa Gray of the Arnold
Arboretum made note of the similarities of American plantsand those
of Asia. He speculated that the glacial editing we had in North
America and Europe wiped out many specie of plants. Those glaciers
did not affect Asia as much. So many Chinese and Japanese plants
are begging to be introduced into our American gardens. Many are
closely related to our own native American plants and are well
adapted to our gardens.
In the last
two decades S.Africa and Chile have become the new resource for plant
introductions. We are fortunate that they adapt well to their new
homes. With good judgment and proper placement they can be a joy. My
talk will be about bad judgment and improper placement as that is the
type of guy I am.
With the cornucopia of plant material we are
now introducing, some material is questionable and aside from the
investment may well create future problems as we now discover that
these "adventuresome" plants have become weeds requiring
much labor or herbicides to remove from our landscape.
"Dan
Hinkley of the Heron people often used adventurous” and other such
descriptives such as “likes to travel”. I don't know about you,
but when I plop a plant into the ground, I expect it to stay put and
not to stray. I could buy a dog or cat for that purpose. Look
seriously at the ornamental merit of all your plants and avoid those
that only create work opportunity for the gardener you hire.
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I
will not dwell on particular plants but on the general reasons for my
deletions. I will not only insult retail and wholesale nurseries that
peddle these invasive plants, but I am sure I will insult some of
you. I just began a new job and saw Cape Fuchsia widely planted. It
was my first negative comment on the garden. I still got the job.
More interestingly I had not mentioned one invasive weed,
that being oxalis. I figured anyone dumb enough to buy that deserves
what they get. HHMN, I am sounding like that elitist Ann Loveloy, and
her talk down attitude to Neophyte gardeners. There are a great many
want-to-be gardeners who get demoralized because they are sold the
wrong plants, given wrong advice or are simply not steered in a good
direction. Why do nurseries get away with it? Don’t know, but if
I went into an auto supply center and asked for oil and they gave me
cheap paraffin: guess what – when the engine seized up I would be
ticked off.
I feel more people should feel equally protective
about their own gardens – or to what they will leave behind.
This is a gardening tale by a Nurseryman who is
now eradicating many of the plants he once sold; it might even be
termed as a mea culpa or a sermon. The Good, the Bad and Ugly of the
plant world.” Yes, there are plants I have come to hate. Many are
invasive, and often are poisonous plants as well. These plants should
come with a warning label.
Consider this lecture as my own
warning label. Or as a British man said:" Not all plants belong
in the choir of your garden.") A Sweet William wrote that there
was no plant he could not like. It was but a challenge to get to know
them better. —To grow closer to them. This not me. I find that
there are some plants I really don’t like.
Did
you really intend to make your house into a Chia planter? (picture)
Some
are based on a weed factor basis, either by stoleniforous adventuring
or by spreading by seed. Some commentary is based on foliage
impairment.
Houtyinia cordata (Korean Ivy) fits in both
categories.
Planting it in a moist border is like inviting the Hell’s Angels
to a choir outing!”
As a nurseryman I will also mention the
cost factors, both in future labor costs and in the need for chemical
use to eradicate plants that ought not to have been planted. Most
Nurseries label these plants as “fills in rapidly” or “easy
spreader.” Beware of using such invasive plants They may be a quick
or CHEAP fix, but your future gardener will have years of labor and
work trying to get rid of them.
Please follow up with your own
problem plants. Some of mine include.
Hellebore (aptly named),
most Euphorbia, Alstroemaria (the species), Lady’s Mantle,
Veronica. Goutweed, Bishop’s weed, some honeysuckles, bittersweet,
a native Ginger (Asarum) and so much more. Polygonum, (Knotwed) or
sometimes called "Mile-a -Minute." Anytime the mail-order company
lables something as "an adventersome fellow," beware!
Trees/Shrubs-
Sumac, Daphne retusa, Stranvaesia davidiana
Last you get into bug or slug magnets.
Pesticides are going to become more and more expensive, so Hosta and
Bergenia come to mind.
Let me know some of your own dirty dozen!
For a quick effect in your garden, choose plants the nursery ahs
labeled “fills in rapidly” or “easy spreader.” Beware of
using invasive plants for ground covers unless they’re contained by
a barrier such as a sidewalk (though such a border won’t stop
invasives that spread by seed). Mint is notorious for spreading
mainly by roots. Put it in a large container, either on your patio or
on pot feet—not on bare ground. Some notorious, but commonly sold,
invasive groundcovers and vines include goutweed or bishop’s weed,
oriental bittersweet, snow on the mountain, English ivy especially.
No sooner are you thrilled that a certain plant is thriving than it
pops up unexpectedly where you didn’t plant it. Then, before long,
it has aggressively spread its way through your garden.
Some
reproduce themselves by seed and replant themselves thanks to ants,
birds and breezes. (Even slugs!)
Others spread aggressively by
stolons (stems that creep along the soil surface, taking root
wherever. Eventually such stoloniferous plants like asters can choke
out or smother their neighbors. Pulling or hoeing them can become a
half-year job as stolons left in the ground just re-sprout. The
upside to these lovely invaders is that they make good soil binders
for slopes, and grow where nothing else will. A good example being
two lovely native groundcovers that I once sold. Vancouverii.
Unfortunately, they are so invasive that they will grow through
dwarf. Azaleas, Mugho Pine and can hardly be pulled out.
Runaways
to watch out for—Illegal immigrants.
Some plants, cannot
be safely controlled. Introduced species once cherished as rare and
special become demons of the woodlands or waterways. Scotch broom
(Cytisus scoparius),and purple loosestrife (Lythrum salicaria and
related species) are examples. Check out The
Federal Noxious Weed Program This is the link to WA state noxious weeds.
Individual states have similar websites. What is noxious in
one place may not be a threat elsewhere. Simple matter of weather.
David Douglas introduced Salal to Britain, we in return were given
Gorst. Plant fanatics are also responsible, finding the native
vegetation boring we import non local wildflowers. Our Olympic
National forests, now have over ninety introduced wildflowers that
choke out what we once treasured. Opium poppies being one of them!
Which brings me to a few
favorites.
Seed-spreaders
Forget-me-nots
(Myosotis). these demure little blue flowers refuse to be forgotten,
persisting for years as they self-sow. Easy to pull where you don’t
want them.
Oxalis (Bermuda Buttercup) Suggested by Carol, an eBayer. Sold in Nurseries and on eBay.
Welsh Poppy. Glorious yellow that fits right in with the above. I
have been fighting those for years.
The
common Viola (Viola tricolor) or even worse Viola labradorica.This
petite flowered member of the viola family so loved relentless
reseeds
Jupiter’s beard (Centranthus rubra). Self-sows
prolifically thanks to small dandelion-like seeds.
Fireweed
though beautiful will spread your garden addition to neighbors a mile
away.
Helleborus niger (never a weed) but its cousin H. orientalis
can be! Same for most of the species.
Helleborus. Not only do
their roots suck the nutrition from anything else, unless dead headed
their seedlings will overwhelm most gardens.
Linaria purpurea A popular perennial, spreads
like crazy. It is on my to kill list wherever I see it.
Same for
Lady’s Mantle, five years ago I killed the last plant in someone’s
garden. Her seedlings are still coming up. A special thank you to Ann
Lovejoy! :-(
Asarum – Wild gingers especially the N. American
variety can throw out thousands of seeds that ants will spread all
over your garden.
Veronica spicata and some other species If you
love their flowers you will soon be seeing more of them. All over
your garden.
Stolon-spreaders
Most
bamboos! Unless you like working with a pickax and pry bar, try not
to put them in your garden unless in containers.
(Physostegia
virginiana). Obiediant plant it is not. It needs to be root pruned
and cut them back all the time. I personally would prefer to do other
things in my garden.
Ground cover asters. Hardy, small-flowered
types sold simply choke the soil with stolons and send up new shoots
everywhere. Curb them with deep six inch plastic edging. Today I
pulled out two wheel barrows of them. They are toast. I will spend
the entire winter watching the bare soil for new surfacings. This
plot will not be plantable until next summer.
(Duchesnea indica).
A trailing ground cover with wiry stems that invest small shrubs or
small trees.This can be a rampant invader both for the stolons and
the berries.
Matilija poppy (Romneya coulteri). A glorious
six-foot-tall, gray green stems produce yellow-centered white flowers
that resemble fried eggs A good plant on hillsides, keep it on the
dry side or contain it like you would bamboo. In an irrigated garden
it can surface six feet away from the original planting.
(Oenothera
speciosa and others).In a rich environment it can become a
pest.
(Vinca major). And Ivies These popular ground covers that
root wherever they touch the ground Supposedly a ground cover, I have
seen Vinca major choke out choice plants by climbing three feet up
their trunks. Ivy of course can make a Chia planter out of your house
or garage. In trees they can grow some forty feet high with their
vines actually sending root hairs into the bark of the tree.
Sweet
woodruff (Galium odoratum). Don’t even get me going on this
attractive ground cover. Given a moist garden it can be a major
problem.
Gorgeous but heartbreaking. Your runaway plants.
Some are even edible, but even my choppers
can’t keep up with runaway mint or Oregano’s—One garden I work
in smells like I’m working in an Italian restaurant, so many
seedlings have spread all over.
Phygelia capenses -- African Cape
Fuchsia
Physalis franchetti(Chinese lanterns) Nursery’s sell
these suckers for 19.95 in five gallon cans never telling the
consumer how invasive they can be Lily of the valley. Is another one,
wonderful but can get so thick you can barely get a shovel into
it.
Rosa witchuriana – A beautiful ground cover rose. But have
you ever tried weeding it? Also when it finds vertical support, hint
your shrubs – it will climb all over them making pruning an
adventure in band-aids and peroxide.
Their could be additional
sub-sections.
Poisonous plants
that children could eat the fruit of.
Laburnums
etc.
Your own Runaway Plants List (Please add your own)
Many of
the sedums
Chives and many of the onions.
The milky sapped
family of Euphorbia.
Bishops weed – anything but holy
Plant
debris or the problem-- what to do
with it? .
Many places no longer allow you to burn, so one has
no other alternative but to shred and compost or to take it to the
dump or recycler. The latter costs five dollars here.
One place I
work for accumulates that load EVERY week. That is a couple of
hundred dollars every year.
That is just a normal garden, with
nothing problematical in it.
However, gardens with Miscanthus and
other large plants end up having to dispose of those leaves. One
large Miscanthus floridilus would nearly fill my pickup. I shall
bring a sample or photo
A special award to those nurseries that still
sell Gorse and invasive oxalis! Who doesn't want a thorny shrub, up 6
ft. tall, with inch-long spines in their garden? This Western
European native was introduced as food plant for sheep and as a
"living fence" The minor drawbacks are:
Forms dense,
impenetrable thickets that allow nothing else to grow . Seeds can
remain viable in the soil for more than 30 years Deep roots help
this plant survive fires, and fire helps the seeds sprout
Just
the type of plant to survive the new global warming landscape.
I
wish to end with a positive note, a poem by Leigh Mercier
To
plant a tree is
an act of faith in the earth,
An act of hope
for the future
An act of humanity towards
Coming
generations
Who will enjoy its fruits
After we shall be gone
:
That is the garden and world, I wish to leave behind, and
this Thursday's child has a long way to go on that score. Something
to think about.
Herb Senft (C) 2009