03 September 2004

A good year for wild grapes

Forrest M. Mims III

Wild grape vines are so common in some states they are taken for granted. They are so common in Ohio that 30 species have been declared as "noxious weeds" by the Ohio Department of Agriculture.

At least four species of wild grapes can be found on our little stretch of Geronimo Creek in South Texas. This has been a very good summer for wild grapes here, and many of those on our place have produced fruit.

Most of these grape vines produce clusters of fruit with pea-size berries. The major exception is the mustang grape, which botanists know as Vitis mustangensis.

Its fruit is similar in size to table grapes. The color ranges from purple to dark black. Clusters of up to a dozen or so grapes are formed.

Mustang grapes can be so acidic that they can irritate skin. One web site suggests wearing rubber gloves when harvesting them.

Yet some mustang vines produce sweet grapes. But because of their seeds and very thick hide, even the sweet ones aren't suitable for eating.

A mustang vine that produced sweet tasting fruit once grew on our place along a fence near Geronimo Creek. That vine met an untimely end in the record flood of October 1998.

Every time Geronimo Creek floods, the ground afterwards is paved with grape vines pushed or pulled down by the water. The sweet mustang was pulled completely out of the ground and washed away.

Most people who harvest wild mustang grapes use them to make wine. A web site by Jack Keller reports there's a mustang grape arbor in Cedar Park, Texas. The owner claims one of the vines is 200 years old, which means it dates to around 1804. I've not been able to find out how one verifies such a claim.

Very young wild grapes grow very fast. They can cover substantial portions of live oak trees in only a few years. A mustang grape vine by our mailbox covered both sides of a 5-meter (around 15 feet) section of a wood fence in only a few months, in the process producing a fair amount of fruit.

If you happen to come across some mustang grapes and want to taste one, caution is advised. One way is to break a grape open with your fingers. If the juice doesn't dissolve your fingers, carefully touch the open grape to your tongue. At least that's my method. I can't guarantee this will work for you, so please be careful.

Forrest M. Mims III and his science are featured online at http://www.forrestmims.org/.

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise, Seguin, Texas. The column is written for a general audience.