
If you've ever ridden your bicycle in the Inland Northwest, you're acquainted with puncturevine. This bane of the backyard is on everybody's black list, and we get calls from late spring to late fall as it takes over more and more of the parking lot, alley, vacant yard, etc.
Tribulus terrestris is a formidable foe, all alliteration aside. It doesn't begin to germinate until it's hot--usually in the high 80s. As soon as it does, it pays to kill it fast, as its entire life cycle can be completed as quickly as one or two weeks. That means it can go from a nasty goat head seed in your driveway to a green plant producing more nasty seeds in 10 days or fewer.
And dang those seeds! Tough enough to deflate your tire faster than you can say, "oh crap," its seeds are even more evil on the paws of your dog and on your own bare feet.
Tribulus terrestris is a formidable foe, all alliteration aside. It doesn't begin to germinate until it's hot--usually in the high 80s. As soon as it does, it pays to kill it fast, as its entire life cycle can be completed as quickly as one or two weeks. That means it can go from a nasty goat head seed in your driveway to a green plant producing more nasty seeds in 10 days or fewer.
And dang those seeds! Tough enough to deflate your tire faster than you can say, "oh crap," its seeds are even more evil on the paws of your dog and on your own bare feet.

In 2016, we had a few days in the 90s in the month of April--that set up the plant for a l-o-n-g growing season that led to even more plants than usual. Typically, people start to watch for it in late June or July, but remember:
Plants and insects don't care about our calendar. Or tires. Or dog paws. They only care about the weather.
And the seeds can lay dormant for possibly greater than 20 years. So since this enemy can seem to grow without moisture and in the worst soil conditions, what's a responsible homeowner to do about it?
Plants and insects don't care about our calendar. Or tires. Or dog paws. They only care about the weather.
And the seeds can lay dormant for possibly greater than 20 years. So since this enemy can seem to grow without moisture and in the worst soil conditions, what's a responsible homeowner to do about it?

Puncturevine is easy to kill once you see green leaves. A little bit of 2, 4-D lawn weed killer will wipe it out fast--the problem is making sure you remember to do it weekly, and getting it done before it grows 15 feet across and has babies of its own.
Prevention is another matter altogether. We have found some success with certain chemistries, but by the time puncturevine germinates (hot), the season for preemergence chemicals is long since past. Not only that, the odds are pretty slim that the tap root is going to suck up enough preemergence chemical to shut it down before it can die due to its metabolic rate.
And why does that stupid neighbor never seem to kill the puncturevine on his side? Probably because he's a lazy nogoodnik, and he's never going to get it. But here are some ideas that YOU can handle!
Prevention is another matter altogether. We have found some success with certain chemistries, but by the time puncturevine germinates (hot), the season for preemergence chemicals is long since past. Not only that, the odds are pretty slim that the tap root is going to suck up enough preemergence chemical to shut it down before it can die due to its metabolic rate.
And why does that stupid neighbor never seem to kill the puncturevine on his side? Probably because he's a lazy nogoodnik, and he's never going to get it. But here are some ideas that YOU can handle!

- Get on our weed plan. We'll keep your gravel free of most weeds, and we can include inexpensive add-on seasonal visits if puncturevine is harassing you or your property.
- Spray it ASAP, and touch it up weekly. Don't say, "I'll do it next weekend," because it may be big enough to reproduce by then.
- Try cooking the seeds when it's cold outside. During burning season (check with your county officials), go outside where the seeds are laying on the soil. Using a torch, cook the outsides of the seeds as though you're toasting a marshmallow. The seeds, fooled into thinking it's summer, will crack open, germinate, and die in the coldness of December or January.
Puncturevine is awful right now, but remember: It can't live forever. Winter is coming.