Exotic Perennials in Western PA

Those of you who have worked our annual booth at the Farmer’s Market have heard it over and over; “Don’t you have any unusual perennials?” Everyone wants the exotic perennial that none of his neighbors possess. Yet the very fact that these gardeners are interested in perennials seems to indicate that they are looking for a plant that will give them good and loyal service, coming back year after year. Not for them the showy annuals that will die at the first frost or the tender bulbs that have to be lifted with the coming of winter. Nope, they want the perennial that will be there in the spring and save them money and effort. None of them ever consider that the search for the unusual defeats the purpose of a perennial.

Think now; why would a plant be scarce in a given planting zone and uncommon in your neighborhood? Why don’t local nurseries provide us with those rare plants that you see so gorgeously displayed in the plant catalogues? Could it be that nursery people are wise in the ways of plants? They know what will grow in our area and what will not make it through the first winter, what will put its sensitive roots down in our acid soil and drop all of its tender green leaves. All of those lovely unusual plants, whose demise is going to send customers back to the store, receipts clutched in their hands, for a refund.

You can find hydrangea’s growing in our area and in some of he local nurseries but they are not common. One of the most striking is “Nikko Blue”. In our acid soil it is a true blue and it is hardy to zone 5. Why isn’t this beautiful native Japanese shrub grown more extensively? Perhaps because most winters it will freeze down to the ground in zone 5 and unless you know that it blooms on old wood you will never have any flowers.

The procedure is to pin the branches down with bricks or blocks and cover with pine needles. This will indeed get your plant to bloom but it hardly puts “Nikko” in the category of carefree perennials.

Nor does the fact that this plant still thinks it is growing in Japan make it easy to care for. The leaves refuse to drop in the fall. It takes a good hard freeze to even kill them and still they persist, wet and clinging. Unless you wait until the weather turns really cold, you will be putting mulch over the branches while the leaves are still on the stalks. If you wait too long, you risk losing the pre-formed flower buds to the cold.

In the spring the new leaves come out in late April or early May. Now you are faced with the dilemma of leaving them covered to prevent them from freezing or uncovering them to allow them some air and light and again risking the flower buds.

Invariably some of the branches have died half way down the stem, so selective pruning is necessary. Unless you prune all the way to the ground, sacrificing the entire branch that you so laboriously got through the winter, next year you will have a Y arrangement that will not support the flower heads. This plant is more trouble than your average annual.

Then you have the plants that are questionably hardy. The autumn clematis (C. Paniculata), another Asian import, is a gorgeous plant that presents us with fragrant flowers in early fall when blossoms are scarce.

In zone 7 where autumn clematis thrives, it is an evergreen. It dies back to the ground every year in our area, which is not a problem since it bloom on new wood, until the spring it doesn’t come back

The same is true of the plant known as Gaura or whirling butterflies (Gaura lindheimeri). It is a native North American plant found in Texas and Louisiana and ranging into Mexico, where it grows as a rangy shrub. This plant will grow quite cheerfully here and then one spring, like the autumn clematis, it does not return.

Perhaps there is a clue as to what happens to these plants in the fact that they grow differently in warmer and/or dryer climates than they do here. These plants are marginal in our area; they grow but do not quite fit. They make it through mild winters but then we get one of the really bad ones and the plants do not survive. Perhaps there is not enough snow cover to protect their roots or maybe we go into winter with the ground too wet. Whatever the reason these non-native plants expire.

Then there are the plants that hate our area from the minute they put their roots down. Delphinium nudicaule ‘Scarlet’ is one such plant. It is a California native with small red spurred flowers. I bought one at Hanzley’s last summer and had it for less than a month. Since it reportedly likes well drained soil I suspect it succumbed to the heavy clay of my soil and the inordinate amount of rain we had last summer.

This plant is supposedly hardy to zone 5. Of course, since it promptly turned up its roots and died I did not have a chance to check winter hardiness. I later found it described as a “short lived perennial often grown as an annual”. Enough said.

There are exceptions to every experience. Indeed the toad lily (Tricyrtis), an East Asian import that I grew from seed, has survived and flourished for at least 8 years. It lurks in two spots near the house thriving in the light shade. Apparently the root system is shallow enough not to be troubled by the shale used to fill around the house and it enjoys the protection from wind and weather.
I got a Christmas rose (Helleborus niger) through one winter and have great hopes that it will survive a second. Adding a bit of lime to the soil and mulching it is all the care it seemed to require. Still one season is hardly a test. I can but hope that it will be there in the spring.

So the next time someone disparages the daylily (Hemerocallis sp.) or the Shasta daisy (Leucanthemum maximum) as too common, explain why they are so common. They are pretty, they like our heavy soil, they are not fussy about how much water they get and they survive our most miserable winters. They epitomize what perennials are meant to be: hardy, beautiful and carefree plants that loyally grace our yards for many years.

It’s winter in Pennsylvania, and the gentle breezes blow.
About seventy miles an hour, and it’s fifty-two below.
You can tell you’re in Pennsylvania, ’cause the snow’s up to your butt.
And you take a breath of winter air, and your nose holes both freeze shut.
The weather here is wonderful, so I guess I’ll hang around.
I could never leave Pennsylvania, because I’m frozen to the ground! Anon.