Puncturevine, also known as goathead (Tribulus terrestris), has been a problem weed in many locations for a long time, but I can only remember seeing it for the first time in Southern Oregon about 10 years ago.
This is a plant that we should all be aware of and do everything we can to eliminate.
Puncturevine is a tap-rooted annual with small, five-petaled, yellow flowers and small, hairy, opposite leaves. Its tendrils can reach 10 feet in length! It produces thorned seeds, which when mature will split into smaller segments. The thorns dry to iron hardness and can be transported in tires, feet and shoes.
I have a few tips to share that may help puncturevine hunters.
1. Learn to recognize this plant early. Most plants grow to maturity, produce flowers and seeds, then die. This plant starts producing seeds almost immediately after germination. Recognizing it and killing it before seed production is crucial in order to gain control. The midvein on the seedling leaves is a clear indicator that you're dealing with the right villain.
2. Use the right tool at the right time. At seedling stage, this plant can be easily controlled by cutting the taproot, spraying, burning, even pouring boiling water on it. Once it starts producing seeds, however, those methods no longer apply.
The only method for true control at that point is to sever the taproot and bag the plant. Here's why: You can spray the plant and kill it, but the seeds will remain on the ground and germinate. You've killed one plant, but thousands will grow in the years to come. Complete removal is the only way to control the plant once seeds are produced, and I've seen plants as small as silver dollars producing seed.
3. If the plants you're dealing with have produced seed, for Pete's sake, don't drive there! If and when it's safe, get the propane burner out and scorch the area. Even if you don't kill the seeds, you'll burn off the spines, thereby removing its method of transportation.
The city and county have many priorities, so don't be mistaken into thinking that the road frontage abutting your property will be taken care of by someone else.
Remember, properties suffer from lack of weed control along adjacent roads and lose value, so take charge. The city and county appreciate your help. Also remember, if using herbicides, read and follow the labels precisely.
Jacksonville resident Bob Budesa oversaw the noxious weed program with Medford District BLM and helped start the Jackson Coordinated Weed Management Area. Reach him at 541-326-2549 or firstname.lastname@example.org.