The most common question I get for home lawns this time of year is what do I spray to control weeds?
Although herbicides for weed control is important with home lawns, it is the bigger picture homeowners need to focus on. A healthy well maintained lawn has a lower potential of having a weed problem than a poorly maintained one. Proper cultural practices should be the number one step taken to control weeds in lawns. Chemical control should be used along with cultural practices. Weed control in home lawns should be an integrated control process instead of a one step herbicide application.
Most lawns I am called to look at with a weed issue has more going on that what meets the eye. The homeowners typically notice the weeds. What they may not notice is why the weeds are growing in that particular area. When grass becomes stressed it can thin out and make a perfect habitat for weeds. Poorly drained soils, high traffic compacted areas, shaded area with limited sunlight, improper watering causing shallow root depth, low mowing height, and low fertility are just a some of the problems I have seen that have created weed issues. Below is an insert from an article that talked about some of the major management practices that help maintain a healthy lawn. In my opinion a proper soil test should be the #1 recommendation when dealing with lawn issues.
#1 Maintain the recommended mowing height.
- Mow turfgrasses often enough so that not more than 30 percent (1/3) of the leaf blade is removed in a single mowing. If more plant material is removed, the grass can become stressed and more susceptible to disease causing organisms and insects.
- Keep mower blades sharp. Dull blades will shred the leaf tips, causing the turfgrass to use more water, undergo undue stress and have a ragged appearance.
- Raise the mowing height during stress periods such as drought.
#2 Follow proper irrigation practices.
- The most cost-effective practice that enhances turf growth is proper irrigation.
- Apply water when signs of moisture stress (e.g., wilt) are observed on 30 to 50 percent of the lawn. For most turfgrass species, wilted turfgrasses will have a dull to bluish-green color, leaf blade folding or rolling, and footprints will remain visible for a minute or longer after walking over the area.
- Apply enough water to wet the soil 6 to 8 inches deep. This is usually equivalent to 1 inch of water or 600 gallons of water per 1,000 square feet. To avoid runoff, the amount of water that can be applied in any single irrigation can vary with different soils. For example, the same amount of water will penetrate deeper into a sandy soil than a clay soil.
- If the soil becomes compacted, loosen it through cultivation such as core aeration. This will help the water penetrate the soil.
- Irrigate during dry periods in early spring and late fall.
- Late afternoon irrigating can encourage disease development. Watering after dew development (approximately 9:00 p.m.) and before sunrise (approximately 6:30 a.m.) is most efficient and will not increase disease problems.
#3 Apply fertilizer and lime according to soil test recommendations.
- Disease incidence can be increased by imbalanced fertility and improper fertilization.
- On warm-season turfgrass species, withhold the first spring nitrogen application until soil temperatures at the 4-inch depth are consistently 65° F.
#4 Remove excess thatch.
- If the lawn is not mowed, irrigated and fertilized correctly, thatch accumulation could create a problem.
- Excess thatch reduces water infiltration, creates shallow-rooted turf and encourages insect and disease problems. Disease-causing organisms and insects often survive and multiply in thatch.
- Excess nitrogen can lead to thatch accumulation.
- If excess thatch accumulates, the lawn will feel soft and spongy. For a thatch layer thicker than 0.5 inch, dethatching is advised.
#5 Allow for adequate light and air movement in shaded areas.
- Raise the mowing height in shaded areas to help the plant absorb the light that does penetrate the tree canopy.
- Design landscape plantings so that trees and shrubs do not restrict light penetration or air circulation to the turfgrass canopy.
- It may be necessary to prune nearby trees and shrubs to improve light penetration and air movement.
- In shaded areas, excessive moisture can persist within the grass canopy. Disease-causing fungi use this moisture to survive and infect the grass.
- Reducing fertilizer amounts by 20 to 50 percent compared to grass in full-sun areas also helps the grass in limited light environments.
#6 Follow recommended disease, insect and weed control practices.
- Correctly identify the disease, insect or weed prior to treating with a pesticide.
- Proper management practices can reduce pest problems and reduce the need for chemicals
Full UGA Article on Weed control in Link Below.