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Oakleaf Hydrangea |
In early January, Penn State Extension conducted a “Green Industry”
conference at Delaware Valley College. We’ve
been collaborating with DelVal, The Pennsylvania Landscape /Nursery Association
(PLNA) and The Professional Grounds Management Society (PGMS) for about 30
years to bring professionals in the green industry together for a day of learning
and socializing. This year 175 people participated.
The afternoon keynote speaker was Dr. Harold Sweetman, Executive
Director of the Jenkins Arboretum. Harold’s presentation was spellbinding. Great
photography and beautiful plants are a winning combination. His message was
about Green Medal Plants … plants native to the eastern United States that
thrive in the Delaware Valley region and would be beautiful in residential and
commercial landscapes throughout southeastern Pennsylvania. The
designation is made by Sweetman and the Jenkins staff.
Here, I’d like to share thoughts on a few of the Green Medal
trees and shrubs. There are also Green medal herbaceous plants...wildflower
and ferns. But I’ll stick to the woody
plants because I know them best.
You can see the entire list here
http://www.jenkinsarboretum.org/greenribbon.html.
And, I certainly won’t attempt to compete with the Harold's photographs by
including lots of pictures! I encourage you to see multiple images of each species
at the website link shown above.
One interesting thing about the Green Medal designation…. it
is for the species not specific
cultivars. For some plants (think Cornus
florida) you’ll find many cultivars. But the focus of the program is to
make us more aware of the species in general. You can branch out from there.
Ok, on to the plants. Maybe the reason I warmed up to Harold’s
presentation so much is because I see the plants he discussed almost every day.
I have most of them in my front or backyard. And we have some of them in the fledgling
Almshouse Arboretum on the grounds of Neshaminy Manor Center where Penn State’s
Extension office is located.
So here are a few woody plants that you really should consider
adding to your landscape this year. What? You don’t have a landscape of your
own? OK. Find a park, school, church, or other public area and set a goal to
obtain each of the Green Medal plants.
Eastern Redbud.
Cercis canadensis – not red buds…. purple/lavender
buds! Before the leaves emerge! That last for weeks! This plant is simply
stunning in early spring. White flowered forms are available. And, it also has beautiful
clear-yellow fall foliage. There are many cultivars with interesting summer
foliage... even variegated, if you must. Small tree. Fits into existing landscapes.
Common Pawpaw. Asimina
triloba – Ok, not so common. Of all the plants on the list, this one may be most
unfamiliar to you. But after hearing Harold describe a Pawpaw Daiquiri, I know
it has a future. My plants are still young and have not yet borne fruit. But I have eaten it and they are as tropical
tasting as a mango or bannana. Just wild. Pawpaw is tolerant of shade and mucho
soil moisture which makes it a good fit for such otherwise challenging sites.
Get at least two different individuals to insure cross pollination for fruit
set.
Carolina Silverbell. Halesia carolina
or Halesia tetraptera - Looking for a small to medium sized, shade tolerant,
flowering, native tree. Gotta have
Carolina Silverbell. Silverbell refers
to the white flowers that hang downward from the previous season’s growth. This
plant requires good soil... .deep, moist, acidic, well drained but it will
reward you with its unique attributes.
Sweetbay Magnolia. Magnolia virginiana – A semi-evergreen small tree. Ok, I just looked
and the specimen at the Almshouse Arboretum is leafless. But the one year old
stems are bright green! This magnolia is noteworthy for it flower fragrance. Shade
and wet tolerant. Foliage is dark glossy green on top and silvery beneath. Shade and soil moisture tolerance is a big plus.
Alternateleaf Dogwood. Cornus alternifolia – Here’s a plant I really want. And I hope I live
a while because the older specimens have such great character. The appeal of
this dogwood is not the flowers, foliage or fruit but the horizontal branching
habit. Yes, it has flowers of consequence but since they appear after the
leaves they do not have the impact of flowers on Cornus florida. Speaking of which, the very common Flowering Dogwood
is still a great plant. In fact, it is hard to beat for flowers, form and fruit.
With close to 100 cultivars and subspecies in the trade, you will have no
problem locating something you like. Put it at the corner of your house, plant three
or five in a cluster near a woods edge or set one as a specimen in front of a wall.
You almost can’t go wrong with what plant authority Michael Dirr calls “the aristocrat
of native flowering trees”.
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Winterberry Holly |
Winterberry Holly. Ilex
verticillata – Want to make a big splash of color in you landscape? In
mid-winter? Look no further than this native, deciduous holly. These plants are
widely sold and dozens of cultivars exist. They have been bred and selected for
heavy fruit set. I know a guy who has three acres of them that are cut for the florist
trade. Red and yellow fruit are possible with red predominating. Yes, you’ll
need one, dull male. That’s life. And there is not much sense in having a single
female when half a dozen will really liven things up. These plants tolerate
very wet sites. What better way to solve a landscape problem than by filling it
with color. I have never seen a serious pest on this species.
Franklin Tree. Franklinia
alatamaha – We don’t have space here to tell the fascinating history of
this plant. And for landscape purposes I guess it doesn’t matter. This small
tree (10-25 feet) produces beautiful, large, fragrant, white flowers with bright yellow centers in
mid-summer… for starters. Fall color is a beautiful reddish purple. The dark, fluted
smooth bark and interesting branch architecture
make it interesting when dormant. Hard to transplant and maybe difficult to find
except at specialty retailers.
Most, (probably all) of these plants have important relationships
with native insects and other critters. When you fill your landscape with such
plants, you are not the only one who benefits.
One thing I have noticed over the decades of involvement with
the Green Industry Conference at Delaware Valley College...we have no trouble finding
outstanding horticulturists, like Harold Sweetman right in our own back yard. Kind of like these
native plants… you don’t have to go far to find a winner.