Xtremehorticulture

Xtremehorticulture of the Desert

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

Leave a Comment / bermudagrass, how to, Roundup, tall fescue lawn, weed control /

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

Leave a Comment / Roundup, Saguaro, weed control /

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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Clover-Looking Weed with Yellow Flowers is Very Difficult to Control

Leave a Comment / herbicides, iris, Las Vegas, lawn, Mohave Desert, Mojave Desert, nevada, oxalis, shrubs, weed control /

Q. I have oxalis clover look-alike as a weed. How can I control it? I am ready to use chemicals at this point having tried to rid it by digging and pulling with no success. Having it in my grass is bad enough but now that it is in my iris beds I want to kill the dang stuff! Oxalis looks like clover but has yellow flowers that resemble a daisy with only five petals. A. Oxalis is very difficult to kill. It may require repeat applications but one of the keys is to try to kill it when it is “happy” and is ready to grow and multiply. This is usually spring and fall. Go to your favorite nursery or garden center (you may have to look at several such as Lowes, Home Depot, Star and Plant World). Go to their weed killer section. Look at the active ingredients. Look for the following in the active ingredients list. The important chemicals to find on the label are either Dimethylamine salt of dicamba: 3,6-dichloro-o-anisic acid (it may be just called dicamba or Banvel) somewhere on the label. The alternative would be an ingredient called triclopyr, (chemically called 3,5,6-Trichloro-2-pyridinyloxyacetic acid) These chemicals are usually combined with other weed killers for better synergism (efficacy or improved performance). In cases of herbicide synergism 1+1 = 3 times more effective. So you may see 2.4-D listed as the first chemical (Dimethylamine salt of 2,4-dichlorophenoxyacetic acid) or you may see 2,4-DP (mecoprop or Dimethylamine salt of (+)-(R)-2-(2 methyl-4-chlorophenoxy) propionic acid) listed as well on the label but the names in RED are the most important for oxalis control. I am sorry for the detailed technical response but this is really technical stuff to get you the right chemical. There are so many different manufacturers and labels with the same stuff in it, it is impossible to list them all so giving you the ingredients to look for is much easier. Next is the method of application. These chemicals will not damage a lawn if you apply at the right concentration but they WILL damage other plants. So you must spray them directly to the weeds and not overspray onto other plants!  Make sure you wear waterproof gloves when mixing and applying and wash thoroughly after an application. They are not THAT toxic but it is always a good precaution. Never spray on a windy day. Spray when weather is warm but not hot because the plants are better able to “absorb” the spray.  Mix about 1 tsp of ivory liquid detergent per gallon of spray to the finished mix and thoroughly stir it. Do not add it before you add water or it will just give you a lot of weed killer bubbles. This detergent helps the week killer enter the leaves.

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Preventing Weeds From Growing on Top of My Weed Barrier

Leave a Comment / geotextile weed barriers, herbicides, preemergent herbicides, weed control, weed control without chemicals /

Q. Weeds that infested an area of my yard – there is a screen like barrier just under the top soil. My question is what can I do to prevent this in the future without killing the shrubs in this area and what is the best method to eliminate the weeds that do emerge. I pulled and dug these and don’t want to have to do that again in the future. Weed barrier or geotextile under nursery containers to prevent weeds from growing A. I am assuming the screen like barrier may be a geotextile used to prevent weeds that might germinate and grow up underneath and through it. These are frequently laid on the soil surface with a 2 to 4 inch surface mulch applied on top of it. The surface mulch helps to shade the barrier and prevent the germination of weed seeds beneath the barrier. We do not use sheet plastic for this purpose. That is a huge no-no which is another topic in itself. Weeds such as bermudagrass and nutgrass can grow through the barrier and the mulch but it can be very effective in preventing other weeds. If bermudagrass and nutgrass weeds are close to a source of water such as a drip emitter or a leaky hose they will have no difficulty growing through the barrier and through the mulch. Weed barrier down. Lets air and water through to the soil. The other problem with textile barriers covered in mulch is that windblown dirt is trapped by the rock mulch and falls on top of the textile barrier. Over time, this windblown dirt accumulates and forms a soil layer on top of the textile barrier in amongst the rocks. Weed seeds then blow over the rock mulch or might be carried by birds where they fall between the rocks and onto the soil on top of the barrier. If there is rain or a source of water, weeds will flourish and the textile barrier appears to fail. The barrier has not really failed. The accumulation of windblown dirt on top of the barrier is a major culprit. Weed seeds below the barrier are still prevented from penetrating the barrier and making it to sunlight. Geotextile barrier There are three things which you can do to help prevent weeds from getting established. The first is to make sure your sources of water are limited to only where the plants are growing. If you have water that is spraying onto the rock mulch or puddling into open areas from other sources than you are going to have problems. It is imperative to make sure water is contained in the area where plants are growing. Secondly, it is best that mulches are deep. A 4 inch layer of mulch is much more effective at controlling weeds than a 2 inch layer. Coarse mulches are more ineffective at controlling weeds than fine mulches. By a coarse mulch I mean rocks that are at least 1 inch in diameter.           Thirdly is the point you are probably not going to like and that is staying on top of weed growth. We have an old saying as gardeners that basically says one year of weeds leads to seven years of weeding. This just means that if you fail to control weeds in your garden area and let them go to seed then the seeds released by these weeds will lead to seven years of weeding. It is so very important to stay on top of your weeds and get them removed before they form flowers. There are several types of garden hoes that are very effective. For bare soil or very fine mulch I like the diamond hoe. For larger mulch pointed hoes or even a shovel works well. If the weeds are relatively large, spraying the area with water from a hose and hand pulling weeds about 15 minutes later is very effective as well. Black plastic when laid under rock starts to poke through in a couple of years. Very ugly. Black plastic is a temporary mulch and rock is a permanent mulch.           To aid the gardener chemical companies have developed weed killers that can kill seeds as they are germinating or kill the plants after they have grown from seeds. Many of them are very effective however you are applying and unnatural chemical which is potentially, and in varying degrees, dangerous to other plants, animals and our environment.           Check with your local ordinances but there are devices which use fire to control weeds. These frequently operate off of LP gas with some sort of torch. These are also potentially very dangerous and should be used with extreme caution.           In a nutshell, there is no magic bullet except to make sure water goes where you needed to go, increase the depth of your mulch layer and stay on top of your weeds and do not let them go to seed.

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