Xtremehorticulture

How to Get Rid of Bermudagrass Weeds in a Tall Fescue Lawn

Q. How can I get rid of bermudagrass now, growing in a tall fescue lawn. Bermudagrass invasion of tall fescue due to irrigation and mowing height. Keep mowing height at least 2 inches for tall fescue and keep it full and lush. A. The best way to get rid of it in fescue is to cut it out if possible and then seed the bare spots after the Bermudagrass has had time to die. The best time to do this would be about April or May when Bermudagrass is starting to green up. You’ve got to kill the Bermudagrass when its alive, which starts growing in late spring, and seed the bare areas after all the grass in that area dies. That’s tricky because Bermudagrass is a warm season grass and doesn’t start growing until about mid-March or early April. It’s easier to control fescue growing in a Bermudagrass lawn while the bermudagrass is dormant (sleeping and dead looking). The fescue in the lawn is cool season so you can begin seeding when it’s cooler. But bermudagrass is warm season so it doesn’t “wake up and start growing” until late spring. If you want to try that then I would recommend spraying Roundup (its the only systemic grass killer available) in spots where the Bermudagrass is growing in the late spring and wait about a week. Don’t use Roundup combined with any other weed killer. Just plain old Roundup. The systemic Roundup translocates and kills some of the roots of bermudagrass.  First, cut the grass in the Roundup-applied area shorter and seed directly into those spots. Because Roundup is systemic and slow acting it will continue to kill the bermudagrass. The label on Roundup prevents you from seeding any sooner than this. You should start seeing the fescue pop up from seed in about 7 to 10 days as the grass in those spots continues dying. What to Do? 1. Mow the area shorter. 2. Spray Roundup over the area without any other weed killers in it. Just plain old Round-up. The grass wont die for 2 to 3 weeks.  3. After one week, seed a high value tall fescue seed in the same area. The grass you sprayed will look like it is alive but it is dying. I would mow the area shorter, somewhere between a half to an inch tall, and apply ammonium sulfate (21-0-0) in early March. The Bermudagrass likes warm weather, as well as nitrogen fertilizer, and it will start turning green a couple of weeks earlier than when it is taller. Use a high-quality tall fescue variety to seed in those spots. The grass will not be dead yet but it’s dying, and you have to trust that it’s dying. As the new fescue seed is coming up you will see sprayed areas start to die or turn brown. You can safely seed into Roundup-applied areas 7 to 10 days after the spraying has been done. The tall fescue and Bermuda does not look dead yet, but they are dying. You can’t start killing Bermudagrass until after it starts getting green in the spring. Preventing Bermudagrass Invasion In the future keep your mowing height between two and three inches. Keep the lawn thick to choke out any invading Bermuda grass. To do this apply fertilizer to fescue lawns at least 4 times per year; Valentine’s Day, Labor Day, Memorial Day, and Halloween. The fertilizer to use is a 21-7-14, between half to 3/4 of the bag rate if you are returning the clippings to the grass (not bagging). The rate on the bag may be too much fertilizer. Don’t give the edges of your lawn of bevel cut because it encourages in Bermudagrass invasion. Instead use a steel edger perpendicular to the edge of the lawn.

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Roundup Does Not Cause Root Damage of Saguaro If Properly Applied

Q. My Saguaro cactus is beginning to lean and I’m afraid it will fall over. Landscapers were spraying weeds with Roundup on top of the soil near it. Will Roundup hurt my Saguaro and Prickly Pear cacti?  Did the Roundup make the Saguaro lean by hurting its roots? Do you know anyone in the Coachella Valley who can put a brace on it so it doesn’t fall over? A. To kill or damage plants, Roundup must be sprayed onto the green parts of the plant. Older parts of the plant which are not green or no longer green won’t absorb any. If your gardeners sprayed the ground surrounding the Saguaro there should be no problem for the Saguaro.             There is an exception. Roundup can move in water and cause damage. Never spray Roundup where there is moving water.             Any pesticide including Roundup can move with wind or significant air movement. Never spray when there is air movement over 2 mph. never spray the hot surface of a soil or rock because pesticides can volatilize, move upwards with warm air and damage plants.              As long as landscapers or applicators are careful around plants there should be no problems.             In my opinion, the reason your Saguaro started leaning is because of how it’s irrigated. Saguaros support themselves with roots that extend long distances from the plant. This stabilizes it as it gets taller.             If irrigation is applied close to the trunk and there is no other water available then roots will not grow very far. As it gets larger, it gets top-heavy and these short routes can no longer keep it upright.             What to do? I sent you a picture of how to properly support a Saguaro after it has been planted and until I can get established. Install other plants with drip irrigation at several distances away from the Saguaro. If the soil is wet, the roots of the Saguaro will find this water and grow further from the trunk.

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