Gardeners have yet to take field bindweed as seriously as rural landowners do. So, the plant-strangling, perennial vine is making real inroads into urban landscapes.
"In Kansas, bindweed is a non-native, invasive plant and official noxious weed. It already had destroyed millions of acres of crops before it first made its way into town," said Ward Upham, K-State Research and Extension horticulturist.
While the weed is still actively growing, however, fall can be a good time for urban dwellers to start fighting back, Upham added. Then they'll need to remain vigilant for years.
Bindweed produces an almost delicate-looking vine. It has heart- or shield-shaped leaves and small trumpet-like flowers in pink or white.
"Until it flowers, bindweed can do an amazing job of blending in. It can look like another lawn weed. It can wrap so tightly around stems that it seems like part of a shrub or perennial," Upham said.
Bindweed sends roots both down and out. Unchecked, they can eventually reach 30 feet long. Each bud on the sideways roots can produce a new plant or send out more roots.
To curb that growth now, Upham recommends unwinding several feet of the vine, laying them out flat and spraying with a glyphosate herbicide (Round-up, Kleen-up, Killzall, etc.), following label directions.
"This is a non-selective product, so choose a still day. Also protect nearby plants from spray drift, perhaps using a big piece of corrugated cardboard," he advised. "If you spot spray your lawn, try a cardboard tube."
Lawn-wide treatments can be disappointing, but better than nothing on established turf, Upham said. The herbicides for that approach are dicamba (Trimec, Weed-B-Gon, Weed-Out, etc.) or – even better – quinclorac (Drive, Ortho Weed-B-Gon Max + Crabgrass Control, Bayer All-in-One Lawn Weed and Crabgrass Killer).
"Next year, start pulling up emerging bindweed before it develops six leaves. With six leaves, the plant can produce enough energy to start strengthening its roots," he said. "If you see a missed vine later, pull it up, too -- even though that won't kill the plant. Each bindweed produces an average 550 dark-brown seeds per year. The seeds spread easily and can remain viable in the soil for 50 years."