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weed and seed for bermuda grass

Mowing: The ideal mowing height for bermudagrass is from 1 to 2 inches depending on the specific site and management regime and is best determined by the conditions in the lawn. Start the season by mowing the lawn at a height of 1¼ to 1½ inches based on a bench mark setting. This is the measured distance from the mower blade to a hard surface and can easily be determined by using a small ruler. Mowing heights below 1 inch will require a reel type mower to achieve satisfactory results. Over the next several mowings, gradually reduce the mowing height in as small an increment as possible. Monitor the lawn after each mowing. Once a height where the grass does not look good anymore, it looks too thin or scalped, raise the mowing height back to the previous setting. However, cultivars of bermudagrass that are adapted to acceptable growth in partial shade may be best cut at a 2-inch height.

Trent C. Hale, PhD, Former Extension Turfgrass Specialist, Clemson University
Chuck Burgess, Former HGIC Horticulture Extension Agent, Clemson University

May Through August

Gary Forrester, Horticulture Extension Agent, Horry County Extension Service, Clemson University

During periods of environmental stress due to high temperatures or a lack of rainfall, raise the mowing height until the stress is eliminated. Always mow with a sharp mower blade using a mulching type mower, which leaves the clippings to decompose on the turf. The mower blade needs to be sharpened on a regular basis – usually about once a month or at least before the growing season starts. If the bag is picking up soil, especially sand, when the lawn is mowed, then the blade may need to be sharpened more often than once a month.

The date of initial turf greenup can be quite variable. In the coastal and more Southern regions of South Carolina, this generally will occur sometime during April, but further inland, this may be as late as mid-May. It is not unusual for bermudagrass to green up and get burnt back several times during the late winter or early spring due to late season frosts. Because of possible injury to the lawn and the potential fire hazard, do not burn off bermudagrass to remove excessive debris. For more information on mowing, refer to HGIC 1205, Mowing Lawns.

If your lawn is still overrun with weeds in mid-summer, consider using a combination fertilizer/post emergence weed control (granular) when you fertilizer around July 1. Follow the labeled instructions and make sure your lawn is wet when you broadcast the product.

LATE WINTER: Apply a pre emergence weed control when the soil temperature reaches a consistent 50 degrees. This is usually February or early March, when the Forsythia is in bloom. This application will control annual weeds and perennial weeds that germinate in the spring. Make sure the product is approved for use on Bermuda grass and apply at the recommended rate. Do not aerate (core) for 3 months after you apply pre emergence weed control because it will affect the chemical barrier. Irrigate after applying useless otherwise state on the bag. Do not use a pre emergence weed control that contains fertilizer. If you fertilize now, you might stimulate your law to break dormancy during a warm spell, only to be damaged by freezing temperatures.

TIP: Neighboring lawns, woods and adjacent untended areas product enormous numbers of weed seeds that blow into your lawn. If possible, mow or "weed-eat" them to prevent seed formation.

Types of weed control for Bermuda Grass

EARLY FALL: Wait until soil temperatures drop to 70 degrees to apply pre-emergence weed control (without fertilizer) to your Bermuda grass lawn. This is usually around September 15 in the upper South and October 15 in the lower South. If you think you will forget, you can apply pre-emergence weed control when you fertilize in early September but you will be sacrificing some effectiveness. This application will control weeds like annual bluegrass and henbit to germinate in the fall and winter.

POST-EMERGENCE WEED CONTROLS: kill weeds that are already growing in your lawn. These products are referred to as "selective" since they are targeted at specific annual and perennial weeds listed on the label. Usually, controls will either treat grassy weeds like crabgrass or broadleaf weeds like chickweed. Choose the weed control spray that best suits your needs. You may need to purchase a spray for each category of weeds. In most cases, post emergence products are designed to disrupt one of the weed’s critical metabolic processes and should be sprayed when the weed is actively growing. If the weed is dormant because of cold weather or drought it may not die. Post emergence products are most often sol in liquid spray. The liquid sprays are very effective when weeds are young and actively growing. Spray on a day when your air temperatures are 60 to 80 degrees and the grass is dry. Avoid spraying during the 4-6 weeks in the spring when your Bermuda grass is greening up. Post emergence weed controls are sometimes sold in granular form that is spread with a fertilizer spreader when the grass is wet. The dry particles need the moist to adhere to the weed leaves.

While it may be hard to believe most weeds blow into your lawn as seeds and sprout the minute they find enough bare soil moisture, and light to grow. This is true for both annual and perennial weeds. Annual weeds sprout, grow, flower, seed and die within one year. Perennial weeds sprout from seed as well, but the weed plant continues to grow and spread for more than one season (even though the top may die back in the winter).

Weeds enter a lawn for one reason: your lawn is not growing well. In fact, two of the most common reasons for weeds in a Bermuda grass lawn are drought and shade. It is not that drought and shade increase the number of weeds or weed seeds trying to creep into your turn. Instead drought and shade cause Bermuda grass to thin, thus offering weed seeds an open space to germinate and grow. Your trouble may be different. Compacted soil, cold damage, insect/disease damage, flooding, steep slopes (causing dry soil), lack of fertilizer, and irregular pH can cause Bermuda grass to thin. The underlying point is that a thick, well grown stand of Bermuda grass is the first step toward "closing the door" and stopping weeds. Even then, most of us will have to employ various weed control measures to keep our lawns weed free.