Q: Dear Steve,
I rec’d from a friend of mine what she called “pencil plant” a few years ago. I put it in a bed where it is now taking over at rampant speed. I am trying to get rid of it, to no avail. My latest attempt was to break it off appo 2″ from the ground and spray it with a season-long ground and weed killer, and it just moves over and sprouts elsewhere.
I looked up “Pencil Plant” on the internet, and this is not like what I found there. This plant is just a cluster of straight green shoots with dark bands along it. It is a medium green, and actually attractive. It just need boundaries, which I have found out the hard way.
Please let me know if you have any tricks I haven’t tried.
Thanks, Maybeth Gilbert
A: As I always warn readers, be a little suspicious when a friend is really eager to give you a plant. There may be a good reason why.
In your case, you did not receive the true “pencil plant” or “pencil cactus” (Euphorbia tirucalli), which is not a cactus, but a popular succulent with thin, rodlike stems that’s often grown as a houseplant. Here is a link to show what I’m talking about.
What you were given was just about the most invasive weed around, a survivor from long before the Age of Dinosaurs called horsetails (Equisetum hyemale). This plant consist of hollow, bright-green, erect stems with black and gray rings. It produces spores, not seeds, and spreads aggressively by rhizomes, especially in moist or wet soil. Once established, it is very difficult to eradicate. You could try painting the stems with Brush-B-Gon (triclopyr), but you’ll probably have to repeat this from time to time.
Gardeners Beware!! The only safe way to enjoy horsetails in your yard is by planting them inside a sealed container with no drainage hole. You can sink the container in the ground, but make sure at least an inch or soil of the lip rises above the soil surface. Don’t worry about drowning the plant. It grows perfectly well with its roots underwater. Grumpy
Wow! Thanks for your speedy reply. I have been a Southern Living subscriber for years and learned many good tips from you guys. I will let you know how the brush b gone works. I have truly tried everything I could think of and anything anyone suggested.
Sincerely, Maybeth Gilbert