Question of the Week Number 2: July 12, 2018

“Neil, neighbors have trumpetvines growing on their side of our fence. However, sprouts are coming up all over our backyard. How can we get rid of them?”

The native form of trumpetvine, or trumpetcreeper is extremely aggressive. It spreads rapidly simply by its vining growth. It seeds freely by its elongated fruit.

Most frustrating of all, though, one native trumpetvine can send up scores of sprouts from its assertive root system. Those root sprouts may pop up 30 and 40 feet away from the mother plant, and by the time you add them all up, there can be hundreds of them. Pretty soon, you have a thicket.

You think about spraying them with a weedkiller, but then you wonder that if they’re tethered to the mother plant, if the herbicide might do serious harm to it. And yes, you’re right.

 

So you think about digging them up, but you figure that there will be many more to take their places. And you’re right.

By then you’ve almost run out of options. That’s when I step in with two unusual ones. Neither may seem entirely palatable, but I’ll spout ‘em out anyway.

1. You might talk to the neighbors. If you’re sick of the sprouts, odds are they are as well. Their backyard is probably just as full as yours is. Offer to pay to have the plant taken out. Offer to pay to have a replacement vine put in. Yes, there will be a bunch of additional sprouts for a year or so. If you’re so inclined, offer to have those taken care of as well.

2. If that doesn’t go over so well, it may be time to put in a barrier. You can stop the spread of their plant’s roots into your backyard if you install a root barrier 18 or 24 inches into the soil. Corrugated fiberglass would be ideal.

Determine if there are any utility lines that cross through the property line. If there are none, or if you have located any that are there, dig a trench along the boundary. If you’re using corrugated fiberglass, overlap the pieces by 5 or 6 inches to prevent roots from forcing their way through. Bring the fiberglass up to within 1 inch of the soil surface and you’ll never know that it’s there.

Once you have root system cut and the root barrier in place you can start using broadleafed weedkillers (containing 2,4-D) to spray existing clumps, or you can dig them out by hand. Little by little you’ll be able to reduce the numbers until you completely eliminate them.