Gardening column: Managing Smilax in your home landscape | Columnists

Greenbrier may be invading your garden. This stubborn vine looks like the earth reaching skinny green fingers into your trees and shrubs.

Greenbrier is known by many names. Catbrier is one due to the thorny vines that snag trees and shrubs. It is often referred to as smilax, the genus in which it is classified. There are over 300 Smilax species in the world. 25 of them are native to North America and 15 of them are in South Carolina.

Greenbrier grows in moist shade and plays an important role in naturalized areas by providing edible fruit and stems to wildlife. In the landscape, it’s troublesome. The vine emerges from the ground and can remain upright to grab something with twining tendrils. Most Smilax species have thorns along the stem. Botanically speaking, they’re prickles, not thorns. The same goes for roses. Every rose does not have a thorn, it’s a prickle. Thorns are technically modified stems. Prickles are hardened outgrowths of the epidermal layer. Think of the epidermis as plant skin.

gardening smilax stem.JPG

Smilax vines are covered in prickles, a hardened outgrowth of the epidermal layer. Tony Bertauski/Provided

Greenbrier isnt a problem in the lawn because it won’t tolerate mowing. But it can become an issue in planting beds. Most Smilax species can grow 30 feet tall. Even if you prune it at the ground, it’ll keep coming back because of the large, tuber-like rhizome it forms underground. This swollen root structure can be the size of a football in the landscape. In nature, they get much larger. It provides a carbohydrate reserve that allows new growth to return over and over. In spring, a new sprouts can grow 6 feet in a month. I’ve found digging up the large rhizome to be worth the effort since we’re constantly having to monitor for new growth.

To control it for good, you’ll need to remove the rhizome. This can be difficult when it grows under tree roots. If removal isnt possible, herbicides can be effective with multiple applications whenever new growth appears. A freshly cut stem can be painted with a 10 percent Roundup mixture that will translocate to the roots.

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However, the greenbrier isnt all bad. All parts of the plant are edible. The tips of new growth have been referred to as wild asparagus, sometimes called chainey briar. They can be snapped off and grilled or roasted. We once harvested fistfuls of it from the woods and prepared the shoots for dinner. They were interesting. A bit rubbery, but that had more to do with the cook than the plant. I’d be willing to try it again.

gardening smilax stem.JPG

Smilax vines are covered in prickles, a hardened outgrowth of the epidermal layer. Tony Bertauski/Provided

The flowers are tiny and visually insignificant. It’s a dioecious plant, meaning it bears male or female flowers but not both. If it’s a female, it will produce large clusters of edible fruit. Most are black at maturity. A few species develop red fruit. Birds will gladly spread the seeds.

The fleshy root tuber is also edible. According to one source, it was once upon a time carved into pipes. The name “brier” was referring to a briar pipe. Early American settlers also used the root of a tropical Smilax species to make sarsaparilla, an old-timey drink similar to root beer.

There is only one Smilax vine worth ornamental consideration. Jackson vine, Smilax smallii, only grows about 8 feet tall. It’s one of the few greenbriers without prickles on the stem. It can grow in drier and sunnier locations than most other Smilax species. There are much more appealing ornamental vines, but if your goal is to provide a food source for wildlife, this would be a good choice.

There’s only one other greenbrier vine I might consider growing. Carrion vine, Smilax herbacea, smells like rotting meat when in flower. I’ve never run into this species, not that I’m aware of. I probably wouldn’t plant it by the deck.

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