Fifty years ago, when my father was gardening away, little, if any, attention was being paid to what we now term “invasive species.” Nurseries and garden centers were filling our mailbox with printed catalogs offering anything that the proprietors thought would sell. The ads did not explain that some of the products would be bad for the environment, would be harmful to native plants, or soon would be out of control.
Last week, the Northern Neck Master Gardeners hosted a program on invasive species presented by Peggy Singlemann, almost certainly the most famous Virginia gardener of our era. For 30 years Peggy was the head gardener at Maymont, the 100-acre urban park in Richmond, and on the last Tuesday evening of each month she presents the PBS program, “Virginia Home Grown,” a must-watch for all serious gardeners.
In her talk, Peggy covered four centuries of Virginia horticultural history, describing the importation of foreign plants from colonial days to the present. She spoke of her constant battle with invasive species during her years at Maymont and how she coped with them using as far as possible natural means rather than chemical ones.
For novice gardeners, “natural” is another word for the back-breaking physical labor of digging up the invaders one by one. She recommends resorting to chemical means, i.e., spraying with herbicides designed to poison the unwanted plant, only when other means have not succeeded.
Personally, I consider the most egregious invader to be English ivy. When my parents bought our farm over 50 years ago, the vicious intruder did not exist on the property. Today, it poses a constant battle. Although we never planted or brought ivy on to the grounds, it is ubiquitous, cropping up virtually at every tree’s base and spreading wherever it can.
As we did not introduce it, I conclude that it could have come to us from seeds blown by the wind or from a sprig having fallen off of a passing truck properly headed for the dump. Its aggressivity is boundless. Peggy mentioned that fortunately it has a shallow root base, which makes pulling it up easier than the process is for some other invasives. It also can be cut at the base of trees and buildings where it is climbing.
Unfortunately, in one of the nursery catalogs that I receive twice a year the company is offering English ivy for sale, obviously with no disclaimer for the damage it will do to other forms of vegetation. It also offers the burning bush, another invasive that spreads thousands of seeds annually from each mature plant.
Japanese honeysuckle, horribly prevalent everywhere, spreads out of control very quickly and girdles other plants. Chinese privet is another rampant invasive, also offered for sale by some nurseries, as is Japanese wisteria, which I have found only can be slowed down in its attempted takeover of the landscape by the use of herbicides.
Perhaps the most damaging of all is kudzu, the worst local case with which I am acquainted is that on Route 200 near Mount Olive Church. We cannot blame foreign countries for all of our invasive problems, for here in America we produced one of the most detrimental of all in Johnsongrass, which initially was developed for the benefit of cattle ranchers who wanted a rapidly reproducing forage crop for their herds.
Johnsongrass spreads by windblown seed and by rhizomes that have minds of their own. If the plant is dug up, but a small rhizome remains in the ground, it quickly will come back, ready to spread. Chemicals can help in its eradication, but constant attention is essential to keep it from getting ahead. Some Virginia counties, including Northumberland, have ordinances prohibiting it.
Peggy’s talk was a compendium of these and many other offensive vegetative intruders.
Eternal vigilance might be the price of liberty, but it is also the gardener’s price for ending the “liberty” that invasive plants often enjoy.
