Greenbrier, Cowvine (Smilax bona-nox)

Greenbrier, Cowvine
Smilax bona-nox

Smilax bona-nox, also known as cat brier, has many leaf variations. Some are not speckled like this one and younger leaves are not as oblong. A vine or subshrub to avoid due to its spines. (San Anmtonio, Tx.)

We have a similar Smilax here that we call saw brier. It can really cause problems in my woods, climbing up small trees and stopping my passage through the areas it has claimed. Very hard to eradicate...I am starting to spray some of it with roundup, but I am not sure that will kill the roots. Certainly cannot be dug out in my rocky, root-filled forest soil. It makes black berries that the birds eat and then it comes up from seed all over the place. If this ever hybridizes with the poison ivy, look out!

Roundup has killed ones that are very young plants with repeated spraying, but the large ones that have large tubers have never been finished off by it. The leaves die but eventually they come back. Those thorns really hurt and the skin is irritated for so long. Ouch! My husband calls them the plant from Hades (using the other term that starts with an "H"). But a crossbreed of poison ivy and Smilax would sure be a double whammy and a true devil vine.

I'm just glad to finally positively ID that nasty plant that keeps popping up in a couple of beds! Roundup, eh???? Making a note to self to spray that nasty thing and hopefully get rid of it before the tuber grows too big!

That tuber is usually so far into the ground it is difficult to dig up especially when these things are growing amongst your other plants. Also, it sends out runners so it can pop up elsewhere.

we have just started dealing with this plant. I started trimming cedar trees at the back of the property to discern how many live oak were back there. Turns out there are a lot of oaks and this vine has made a true jungle back there. I have experienced all the same injuries, frustrations and have also considered living with them and fighting them on a yearly basis. Our space, however, is much too wonderful to concede to this savage opponent. I had to cut all of the vines off at the ground to clear the brush and trim the cedars. After raking the ground to remove the dried thorny cuttings of the cow vine, all the new growth is apparent. I have found that wherever there are several vines growing together is typically where the root ball is. If you uncover the root ball and spray it with Round Up, it seems to kill the root ball. Killing the root ball does not necessarily kill the tubers, but it does slow their progress until you can dig them up. I have also tried spraying the vines at the root after removing the dirt from around the base of the vine. It appears to kill the vine from the bottom up. If you spray the young vines before they develop their thorns, the Roundup kills them. I am in the process of digging up the dead root balls and find that some of the large tubers do run deeply into the ground. I am spraying the tubers as soon as I cut the root ball loose while they are still fresh. I have sent photos of some of the rootballs, etc to the website. My mother, who is a licensed Master Gardner and is a successful produce farmer as well, recommends that I try Bayer Brush Killer, with extreme caution, as it may kill the trees if it gets into their roots. That will be a last resort.

I now cut the vine down to about 1/2 inch and then brush on Stump Out Stump and Vine Killer. A tedious task; however, for the past 5 years this seems to do the trick. Sometimes I have to cut the it again and reapply. This product works on hackberry trees as well. The largest hackberry tree that I have eliminated was 4.5 inches in diameter. The remaining stump need to have crisscross cuts mage into the top of the stump before brushing on the product.