Ask Mr. Smarty Plants

We are still trying to get our minds around yucca anywhere but in the desert Southwest. Of the 28 yuccas in our Native Plant Database, not a single one is listed as growing naturally in Washington State. However, members of the Genus Yucca are all similar enough that we can talk about them in general terms. You do have a problem getting rid of your unwanted plants. Yucca has a root you wouldn't believe, big and going deep. It propagates itself both by seed and by offshoots, or pups, from the main plant. It sounds like your yuccas think your asphalt driveway is desert land, and is growing right through it.

There is no magic potion. You are going to have to arm yourself with heavy clothes, long leather gloves and goggles to protect your eyes from those stilleto-like leaves, as well as some serious cutting equipment. First, cut down as much as you can of the leaves, or blades, if you prefer. You probably already know that their edges are sharp, their tips are sharp, and they are tough. Begin with the offshoots and work your way in. Any piece of root left in the ground will sprout a new plant. Dispose of these cuttings in heavy paper bags (they'll rip plastic to shreds) and dispose of them. Don't put them in the compost, or pile them somewhere, they stay lethal for a long time. Although we have no documentation to prove this will work, you might ask your nursery to recommend some herbicide that is meant to be painted on cut-off trunks to kill the roots. Cut the yuccas that you can't dig out down as close to the ground as possible, and then paint with the solution.

It sounded like you were planning to keep some of the yuccas. Don't let them get ahead of you again, be vigilant to root out the offsets and destroy them before they get firmly entrenched. The yucca is a survivor, growing in some of the bleakest desert land in the country. Your plants must think they have gone to Yucca Heaven with all that good dirt and water.