Piedmont Gardener

One minute, summer sun kisses green leaves, flowers abound, birds sing. Then you blink, and color happens.

Cornus florida displays peak autumn color.

For some plants, color comes in patches at first.

Like this native Spicebush, Lindera benzoin.

Or this ornamental spirea:

Spirea ‘Magic Carpet’

Fall fruits droop heavy on branches, then tumble to earth.

Chinese dogwood (Cornus kousa) fruits make it impossible to walk without squishing them.

Deciduous hollies haven’t released their leaves yet, so bright berries look like Christmas balls among the greenery.

Native Redbud (Cercis canadensis) seed pods rattle in autumn winds.

Red Buckeye (Aesculus pavia) seed pods crack open and release shiny fruits.

The native Black Walnut (Juglans nigra) has finally dropped all its nuts. For a few weeks, walking beneath it required a hard hat.

Now the walnuts are a hazard to unwary walkers.

This past Tuesday, a strong cold front approached. Thick clouds darkened the sky, winds blew in gusts, twirling falling leaves into eddies of gold and red. Later that day, the rains came — almost two inches.  The trees that always abandon their leaves first took the winds, rain, and ensuing cold air as their cue.

The first native trees to bare their branches for winter in my yard are always the Ashes. Ash trees dominate the active portion of our floodplain — about an acre or so. I think they’re probably Green Ashes (Fraxinus pennsylvanica), but local experts tell me this species often interbreeds with other native Ash species, so I’m not certain.

Their fall color is subtle, but they do cast a distinctive yellow-green glow over the canopy just before they discard their summer clothes.

A floodplain Ash before the rains stripped it of color.

Ashes are not the first trees most folks notice when walking through their native moist habitats, but they are key components. Their numerous seeds are devoured by many bird species, including Wood Ducks.  The larvae of several of our more colorful southeastern US butterflies eat Ash leaves, including the Eastern Tiger Swallowtail, Orange Sulfur, and one of my favorites, Mourning Cloak. This beauty has dark wings edged in deep gold; I count myself lucky when I spot one or two floating through my floodplain, usually on warm late-winter days, when the over-wintered adults begin seeking mates.

Ashes are easy to identify. They have compound leaves. Botanists define a compound leaf as consisting of a set of leaflets. For example, Poison Ivy has a compound leaf. Those “leaves of three” we all look for actually comprise one leaf. Look for a longer leaf stem (a petiole) that attaches the multi-leaflet leaf to a branch.

Click on this image to clearly see these Ash leaves comprised of leaflets.

A casual observer might confuse the compound leaves of Ash trees with those of another Piedmont forest regular — Hickory, but a closer look is all you need to tell the difference. Ash leaves are attached to branches directly opposite each other. This opposite-leaved arrangement is less common in our native trees and shrubs. A single-leaved tree with opposite leaves that we all know is our native Dogwood. Hickory leaves alternate on the branch, plus most have fewer leaflets per leaf than Ash leaves.

After the rains blasted through, the next day, most of the Ashes on my floodplain were bare. In the blink of an eye, their subtle color was gone.

Bare Ash branches contrast with the remaining still mostly green canopy of other species.

This year as the Ashes performed their vanishing act, I got a knot in my stomach. I couldn’t help but wonder if this will be the last year I am able to enjoy their subtle drama. Why?

The Emerald Ash Borer, a non-native, devastating tiny insect, has a confirmed presence in a few NC Piedmont counties just north of mine. This insect has already killed every native Ash tree in many of our northern states. Every single one. They do it in one year. Experts have no idea how to stop them. Here’s the latest information from the NC Forest Service on this Ash-killing bug. Follow the links on that site to learn more.

A key take-away message about preventing the spread of Emerald Ash Borer and several other devastating non-native insects is about firewood. It is critical that any firewood you buy be from local, uninfected trees. Unfortunately, the firewood industry is not closely regulated. Recently dead trees look like a prime source of money to firewood purveyors. More than half the states in the US, including all of the Southeast, have imposed some firewood movement restrictions. Click on your state on this map to see what restrictions apply for you.

Ignorance is our greatest enemy in the fight to save our Ash trees. If you buy firewood, I urge you to learn what counties in your state are still considered safe sources of uncontaminated firewood. Be wary of pre-packaged firewood sitting outside grocery and hardware stores. Odds are it was shipped in from somewhere else. Ask the store manager where the firewood came from, and if he or she doesn’t know, tell them why you won’t be buying from them.

In my area during every impending cold spell, I’ll see folks selling pick-up trucks full of firewood in parking lots. Firewood sales are a supplemental source of income for most of these folks; many of them probably have no knowledge of the restrictions on where they should be collecting their firewood. In North Carolina, no one should be buying or selling firewood from Granville, Vance, or Person counties outside the boundaries of these counties. They are quarantined due to the confirmed presence of the Emerald Ash Borer. Here are the areas in the US with currently imposed Emerald Ash Borer quarantines.

Unless the experts devise a way to kill this insect in the next few months, it is just a matter of a year, perhaps two, before every Ash tree on my property — about a dozen 75-foot trees — will be dead. Their absence in the landscape will be visible to even the most casual observer. What will be less obvious is the disruption in the Piedmont ecosystem where these trees occur. Birds and insects that evolved to rely on Ash trees as a food source will go hungry. If they cannot adapt to other food sources, they will die trying to find Ash trees elsewhere.

No one knows how many components of an ecosystem can disappear before the viability of the entire ecosystem is destroyed, so that the remaining components die. Think of it as an ecosystem-scale game of Jenga. Sooner or later, the wrong piece is removed, and the entire structure fails.

In the blink of an eye, our native Ashes may disappear. How many more blinks before our native forests are gone too?