Lynn Arave, Deseret Morning News
Puncture vine, also called goatheads, covers the edges of a sidewalk on Main Street in Layton.

LAYTON — With the arrival of colder weather and the approach of winter, weed season is over — or is it?

One of the peskiest weeds in northern Utah — whose detriments can extend far beyond the plant's actual life-span — is the puncture vine weed.

According to JayDee Gunnell, a Utah State University Extension Service horticultural agent in Farmington, this notorious weed can be a real nuisance.

It typically grows on the edges of unhealthy lawns. It can stretch across a sidewalk, if not controlled, and also clog the gutters along the sides of highways. While most weeds grow upward, this one stretches out along the ground like a spider web.

"They can build up quickly," Gunnell said. The weed also has a nickname — goatheads, for its thorny seeds.

He said when puncture vines dry up in early fall, they drop their seeds. These are thorny pods, carrying four to five seeds each.

"One plant can produce hundreds of seeds," he said.

The major nuisance from puncture weeds is just as its name implies — its thorny pods are sharp and can be harmful.

For example, they readily stick in bicycle tires and puncture the inner tube, causing a flat tire. They have even been known to flatten some light truck tires.

Pets walking through an area of puncture weed will get them stuck in their paws, causing them temporary pain.

Pedestrians who walk near a patch will likely get some stuck on the bottom of their shoes. Most may fall off soon afterward, but a few may remain and fall off indoors. Later, a barefoot occupant of a house may readily feel their thorny effect.

Gunnell said he's not aware of any unusual surge of puncture vines this year. However, for some reason, the west side of Layton experienced an unusual surge in the weed this year. You don't see many bicycles around there this fall because a lot of them have flat tires.

Sections of sidewalk along Layton's Main Street, between 1000 and 1600 North, are particularly dominated by puncture vines this fall near vacant or unused lots.

According to Gunnell, puncture vine seeds can remain dormant for up to five years. Besides regular weed control each growing season, he suggests collecting the seeds. He said some people use an old piece of carpet, slid along the ground, to help pick them up.

"You've got to eliminate the seeds," he said.

In the summer growing season, puncture weed can go from germination to flower in just three weeks.