Question: Ihave a yucca in my garden that I'd like to get rid of, but every time I dig it out, it just comes back up again. How can I be rid of it for good?
Answer: Many gardeners have a love/hate relationship with yucca plants. A native of southwestern U.S., the plants are tough and relatively carefree. They're drought tolerant, cold tolerant and require very little maintenance. Plus, their sword-like leaves add texture to the garden, and variegated varieties also add a unique splash of color. Though they typically don't flower every year, when the tall flower spikes do appear, they're quite stunning, sometimes reaching 6 or 8 feet in height.
Yuccas are common garden plants in our region because of all of these positive attributes. However, the yucca's tenacity is also its biggest downfall.
The large tap root of yucca plants can grow several feet wide and many, many feet deep. They're fast growers and can quickly become troublesome when new plants spring up next to the mother plant, or the plant starts lifting the sidewalk or invading other garden areas.
Unfortunately, there is no easy road to getting rid of yucca plants, but with a little persistence and some dedication, it is possible.
Cutting the plant down and attempting to dig it out is a good start, but just doing this alone is seldom enough to get rid of the plant. In fact, when you dig up yuccas and leave pieces of the root system behind, they simply re-sprout into new plants a short time later. As you discovered, merely attempting to dig up the plant causes numerous new yucca plants to sprout. Weed killers are generally ineffective because the waxy leaves of the yucca plant prevent these products from soaking in.
Here's the trick to getting rid of yuccas once and for all.
First, cut the mother plant and all of the side shoots all the way down to the ground. Use a digging bar, shovel, pick axe and whatever other tools necessary to dig out as much of the root system as possible, going as deeply as you can. Carefully pull out any pieces of root you unearth and toss them in the garbage. Do not put them in the compost pile or they'll likely sprout again.
Once you have as much of the root out as possible (sometimes this means digging down several feet), do not refill the hole with the soil you dug out, unless you're willing to thoroughly sift it first to ensure you aren't putting any small, severed root pieces back into the hole. I suggest refilling the hole with a blend of new top soil and compost.
Once the hole has been backfilled, cover the entire area, plus an additional 3 or 4 feet of width, with a layer or two of corrugated cardboard. Then, cover the cardboard with a thick layer of shredded bark mulch. The cardboard and mulch will form a protective barrier over the soil and prevent new yuccas from sprouting up.
Do not disturb the area for a full year. The following spring, add another layer of newspaper and more fresh mulch on top of the existing layer of mulch. Again, do not disturb the soil as you do this.
By the second year, the yuccas will be fully smothered and both layers of newspaper will be fully decomposed. At that point, you can safely plant new plants in the area.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is jessicawalliser.com.
Send your gardening or landscaping questions to tribliving@tribweb.com or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.
