Invasive trees

Nature has taken care of some of our invasive trees, and we're working on the rest of them. Invasive trees have a disproportionate impact since they live longer than herbaceous plants or shrubs, and so they'll be spreading their seeds for that many more decades.

Bradford pears

Bradford pear split after an October 31 snow ©Janet AllenOur bradford pear split after an October 31 snow

A blessing in disguise.

Losing our Bradford pear tree (Pyrus calleryana 'Bradford') first seemed like a tragedy, but later, after we learned about its dark side, we felt lucky that nature took care of the problem for us.

For a while, people were reluctant to plant Bradfords because they had acquired a reputation for splitting like this, but then newer cultivars were said to have solved this problem.

This doesn't solve the problem of their invasiveness, though, or the fact that they don't provide anything for wildlife, except perhaps for that other scourge, the invasive European starling, which do eat the "pears" I'm told.

Bradford pears on display(Enlarge) ©Janet Allen
Bradford pears on display

This is but one of the many local examples of how Bradford pears to "decorate" our public spaces. (We pass this group of trees on our frequent walks to the grocery store.)

Of course, they're attractive in this setting, but just because a tree is pretty from people's point of view doesn't make them a wise choice. These trees are increasingly spreading into natural areas, and they're poor substitutes for the native trees that were there before.

Norway maples

Norway maples after a storm (Enlarge) ©Janet Allen
Norway maples after a storm

Another blessing—though very well-disguised.

The legendary (to Central New York) Labor Day Storm of 1998 removed our Norway maples (Acer platanoides) for us.

Our young teen son and his friend took care of all of these trees with small tree pruners. It was a big adventure for them. Ah, to be young!

Kousa dogwoods

Kousa dogwood in flower  ©Janet AllenKousa dogwood in flower

Kousa dogwood (Cornus kousa) isn't technically an invasive plant according to the usual definition. It doesn't (as far as I know) travel into natural areas (perhaps because it's such a poor food for birds?)

But it is invasive in the sense that it's invading our suburbs, institutional grounds, even public areas by being so frequently planted.

It's a disaster for birds since its berries first, are too big for our native birds, and second, are poor substitutes for the nutritious native dogwood berries.

Kousa dogwood berry ©Janet AllenKousa dogwood berry

This kousa berry is very large. When we bought this plant about 30 years ago, I thought it was wonderful that it had such big berries. (Where kousa dogwoods are native, monkeys eat the berries.) Even more for the birds, right? No! Our native birds co-evolved with much smaller berries, like the size of the flowering dogwood (Cornus florida) or the pagoda dogwood (C. alternifolia) berries—berries small enough to just swallow whole, which they do.

When you think about all the millions of kousa dogwoods planted all over instead of native dogwoods, you can imagine the loss to our birds.