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Tuesday - April 29, 2014

From: College Station, TX
Region: Southwest
Topic: Invasive Plants, Herbs/Forbs
Title: Removal of invasive roots of Turks Cap in College Station TX
Answered by: Barbara Medford


I know people have asked you questions about propagating Turk's Cap, but my question is a little different. I have this plant growing in several locations, because I have a large garden with lots of shade. However, I discovered this spring in an area that somewhat confined that the root systems of these plants are huge, hard & apparently indestructible--we broke a large spade/shovel trying to dig them out. The plants are ill-suited to these areas & the roots are growing under the AC unit. So, help! How can I kill (for good) the plants in these areas?


Of course, the hummingbirds do love Malvaviscus arboreus var. drummondii (Turk's cap or turkscap) and so do we, but any plant that is growing in the wrong place should be considered a weed and treated accordingly. If you follow the above plant link to our webpage on this plant, you will find this paragraph under "Propagation.:

"Maintenance: To keep at a desirable height and shape, prune back after a couple years. To keep it waist-high, cut it back to 5 inches after the last frost. Can be kept cut back to give the appearance of a ground cover, though it doesn't spread by either rhizomes or stolons but by layering. Will bloom even when cut short."

Obviously, you have a very good soil, sunlight, etc. for turkscap, so you don't need our help on that. First, you will need to make sure you control any encroaching plant before they get to an inappropriate spot. And, second, you obviously need something more subtle than brute force to get out those plants around your air conditioner.

We urge you not to use sprays as they can disperse to harm more desirable plants, even animals, like people. The first thing we recommend you get is a long-handled pruner, with very healthy cutting edges. When we say long-handled, we mean one that you can stand erect and use, as your back is going to be in enough pain as it is. You want to prevent it the plants in the prohibited area from seeding out however you can, all year round. Cut off the seeding heads and dispose of them where they won't be available to birds for dispersal, nor can be washed onto new ground by rain. Again, that long handled cutter will come in handy.

Now, to get at the root of the matter (pun intended.) Starting from the outer edges of the invasive clump and using the pruner, cut each branch off as close to the ground as possible. Immediately, using a long-handled sponge disposable paintbrush, paint that cut root with an undiluted wide-spectrum herbicide. You need to do this quickly because that cut area is attempting to heal over to protect the very root you are trying to kill.

Between poisoning the roots of that particular clump and removing seeds before they can be dispersed, you will eventually beat back the unwelcome plants.


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