Daniel Gill | 10/24/2015 4:47:53 AM
Here are pictures of a bamboo kind of weed in my mother-in-law's backyard that we are trying to get rid of. We've chopped it down before but I know we won't get rid of it until we get to the roots. Can you recommend something to use on the roots to kill the plant? Thanks so much!
- Heidi F.
This looks like giant reed grass (Arundo donax ). Cut the planting down to the ground. It is late in the season, so it may or may not resprout. If it does, spray the new growth with glyphosate (Killzall, Roundup) mixed at the strongest label rate when it is 8 to 12 inches tall. It will die back (if it does not resprout, it will next spring and you should do this then). Glyphosate is a systemic herbicide that is absorbed by the leaves and is moved down to the roots internally. So, it kills above and below ground parts.
One application of herbicide is not likely to kill this planting. Through next summer, watch for resprouting and spray as needed until new growths are no longer produced.
At that point, the plants will be dead. To reclaim the area, dig out the rhizomes, prepare the area and plant with the desired plants.
Consumer Horticulture Specialist
The LSU AgCenter and the LSU College of Agriculture