Lawns Keep Weeds out from Its Density

Q. I have lots of weeds in my lawn and the more I pull it out, it seems the more comes up! Besides spraying with Roundup, what can I do?

 

A. The density of a lawn prevents weed problems. Weeds invade your lawn because the lawn is not thick enough to "choke out" existing weeds and prevent weeds from getting established.

            A lack of density can be from too much shade, mowing the lawn too short, disease or insect problems, not applying fertilizer often enough or a lack of water.

            Mow at least once a week. Mow tall fescue at a 2 inch height above the soil. Never mow or "weed whack" tall fescue below 1 1/2 inches in height. This opens the lawn up for weed invasion.

Line trimmers used 2 edge lawns like this one managed by a landscape company cuts fescue too short which encourages invasion by Bermuda grass.

            Bermudagrass lawns need full sunlight. Tall fescue lawns should receive no less than 75% of full sunlight. Some people will say 50% but I think that’s right on the edge. If it's less than 75% sunlight, remove or decrease the amount of shade by pruning trees causing this shade.

            How do you know the percentage of shade? Look at the ground under the canopy at noon. The amount of shade is easier to estimate during this time of day. If it’s 100% shade, open up the canopy with a few pruning cuts that remove entire limbs from the trunk.

By looking at the ground beneath the tree you can estimate the percent shade.The percent shade under the canopy of this tree, not out the open, is maybe 25%, not enough for fescue to grow well.

            Lightly fertilize lawns every 4 – 8 weeks when using quick release mineral fertilizers. In most bags of inexpensive fertilizer, half of the rate listed on the bag is enough to apply if you are using a mulching mower.

            Apply quick release fertilizers to fescue lawns 4 times during the year during the major holidays of Valentine’s Day, Memorial Day, Labor Day and Thanksgiving. Bermudagrass lawns are fertilized during the heat of the summer but ending by September 1 if overseeding.

            Slow release fertilizers are applied in larger amounts but less often. They are expensive but they save labor. Make sure a fertilizer application is applied at Thanksgiving if you want to maintain a green fescue lawn through the winter.

Osmocote is a well known slow release fertilizer

            Make sure lawns are irrigated overhead with “head to head coverage” from sprinklers. This means that water from sprinklers are thrown far enough to hit the neighboring sprinkler.

            Make sure water pressure to sprinklers is not above or below the range recommended for the nozzles of your sprinklers. Inappropriate water pressures cause poor coverage of the lawn.

            Avoid disease problems by irrigating during the early morning hours just before sunrise.