Human Flower Project

Monday, April 24, 2006

Ligustrum: There Goes the Neighborhood

A fast-growing landscape favorite of the 1960s and ‘70 shows its ugly imperialist face.

Ligustrum ovalifolium (privet) in bloom
Photo: Habitas

Saturday, we thought we were in for a bit of trash collecting along the creek. Instead, the Austin Parks Foundation had tricked us. We’d been drafted into three hours of muscle-to-root combat against ligustrum, an invasive plant that’s overtaken the neighborhood park.

Mind you, we walk every morning for a good half hour through this park and had never taken any note of ligustrum. To be honest, we’d thought the whole “invasive plant” issue was a sham, the cloak for anti-immigration sentiment. Did we care if there were clumps of non-native mustard blooming along the freeway?

But what a difference a morning makes, especially if one is working out with a clunky iron vise. This tool, provided by the Austin Parks Foundation, could grip a three-inch ligustrum at the base of its trunk, and with a little (or a helluva lot) of leverage, pop that baby right out of the creekbank. Call it Horticultural Pilates.

Seeds of ligustrum are spread by berry-eating birds
Photo: BFNS

Ligustrum, we learn, is a problem all over the Southern U.S. It was introduced as a fast-growing evergreen, perfect for impatient suburban landscaping but a fright over time. The Clemson University botanists write, “Common privet (Ligustrum vulgare) has escaped into the wild in South Carolina to become a weedy and invasive pest. Birds eat the small, black fruit and deposit the seeds everywhere.” There are many varieties of privet, some less invasive than others, but all “have abundant, showy clusters of very sweet smelling, white flowers in late spring.”

So what’s the big deal? Why not let this vigorous plant keep on choogling? Here’s why: “Ligustrum japonica competes with natives for light and nutrients. It outcompetes natives by spreading rapidly and completely covering and toppling small trees and shrubs in the process.” In our Saturday battle, we saw this with our own eyes. Ligustrums had shot up tall through the park. We saw ligustrums growing right next to oaks and junipers, actually squeezing them out: “Move over, old timer!” Ligustrums had leafed out high over head, so the ground below was overshaded and bare. Now we learn, too, “The newly opened understory causes L. japonica to spread rapidly and provide habitat to other invasives, such as Hedera helix (English ivy) and Pueraria montana (kudzu).” In other words, ligustrum is a botanical imperialist.

Is there privet in your yard? Consider trying your hand at topiary. Since ligustrum grows fast, some varieties make ideal hedge sculpture, and with constant trimming, the plant won’t produce berries, meaning fewer ligustrums escaping into the wild.

Here’s a primer from The Nature Conservancy about how to contain privet plants, with a good description of many ligustrum varieties. The report notes, “In North America, Ligustrum spp. have no important pests or predators.” Not true! You should have seen us Saturday, grunting and bouncing on those orange levers, and dragging trees by the score to the curb. We barely made a dent in the problem.

Stacy Park volunteer Bill Bishop, post-shower, and Dinah survey
the handiwork of uprooted ligustrums
Photo: Human Flower Project

Congrats to the Austin Parks Foundation (and our gentle neighborhood general, David Todd) for mustering 1000 volunteers across the city Saturday, even if we DID think we’d be picking up paper cups. We find it amusing that the Foundation chose to fight imperialist plants with a privatizing slogan: “It’s My Park.”

No. It’s not my park. But we love it and will gladly pull out ligustrum again. You bring the orange grippers, we’ll bring the elbows and grunts.