Ask a Master Gardener: Rattlesnake Weeds in My Garden?
By Don Fry,Mobile County Master Gardener, www.mobilecountymastergardeners.org
Our garden beds can be wonderful places to grow flowers, vegetables, and ornamental trees. We turn the soil as we add natural amendments like composted vegetable scraps and damp leaves. Then in the spring, we plant and fertilize to grow healthy plants. But in this area, March showers bring April weeds even before the May flowers we desire. We try to prevent them, pull them, or even use chemicals to kill them.
Some of these weeds are annuals that come from weed seed produced in the garden in years past. Season-long weed control to prevent weeds from reseeding should be a basic part of any weed control program. Controlling weeds by preventing them from making seeds may be a long-term process, but in the end, it is the only sure way to control this problem.
Other weeds are perennials that seem dormant on the surface during the winter and then reappear with a robust root system to take advantage of all the care that we intended for our plantings. One of the toughest in this area is the Florida Betony or Stachys Floridana also known by most gardeners as Rattlesnake Weed; not to be confused with the West Coast’s rattlesnake weed.
Rattlesnake Weed is a delicate perennial, growing from slender underground stems with segmented tubers resembling a "rattlesnake's tail-rattle.” Leaves are opposite each other on square stems, reminiscent of the mint family it belongs to. It flowers when left alone but reproduces primarily by its underground tubers that can look like white radishes. Its proper name reminds us that it is native to Florida and is now found from North Carolina to Texas. Although it will not bite you, the tuber or ‘rattlesnake rattle’ is white, segmented, and typically 4-7 inches long. The tuber spreads underground and will live long after you remove the green top of the plant. New tubers are formed in the spring as the temperatures begin to increase and before the plant goes dormant again in the hot summer.
In home garden beds, the tubers should be removed by digging them out completely to eliminate the primary source for further spread. Mulch and landscape fabrics are not usually successful in controlling this aggressive perennial.
If you must use a weed control chemical in your garden, spot sprays of products containing glyphosate can be used according to label directions. Remember, glyphosate is a nonselective herbicide and will kill or injure any plant it contacts. It can be brushed, or spot sprayed on a calm day, carefully directed on the green growing weed while shielding nearby plants, perhaps with cardboard. The chemical must work its way through the green plant for it to kill the plant from the inside, so don’t cut or pull on the weed before or after you use the chemical. Even though glyphosate is systemic, repeated sprays in spring and fall for two years may be necessary because of the weed’s large tubers and root system. Digging them up works immediately and is safer! Read more in The Alabama Vegetable Gardener, ANR-0479.
Enjoy your home garden this year and remember that you have friends in your local Alabama Master Gardeners and your local Alabama Cooperative Extension Office. There are new Master Gardener classes each year where you can learn home gardening skills. Then you teach others how to apply these skills throughout the community. Call the Master Gardener Helpline 1-877-252-GROW (4769) with your questions.