You’ve worked hard to get our outdoor landscape just the way you want it. Then you begin to notice yellow spots developing on blades of grass all over your lawn. What happened? And what can you do about it?
Assuming that you’re watering your lawn properly and not over-fertilizing, disease and pests are the most likely culprits. The most common diseases are iron chlorosis, which indicates nitrogen deficiency in the soil and yellow patch, which causes large spots or patches with yellow margins in the lawn. As for pests, chinch bugs cause irregular brown spots that turn yellow.
Each of these three problems has its own particular set of symptoms. Iron chlorosis manifests as yellow or striped yellow and green patches of grass blades on alkaline soils with high phosphorus levels. Yellow patch manifests as 6 to 12-inch wide patches on grass blades that occur in areas that are prone to either excessive shade or moisture. Chinch bugs cause yellowing by sucking essential juices from grass blades.
Once you’ve determined the nature of the problem, you can treat it as follows:
Using a foliar application of iron sulfate, spread a one-quarter inch-thick compost over the turf and aerate the lawn twice a year.
The damage caused by this disease is usually no more than cosmetic. But if the outbreak is severe, you may need to use a registered fungicide.
Aerate the soil one to two times a year to treat chich bugs and apply a registered insecticide to deter them.
If the problem is with how you are watering your lawn, grass blades will look different than if they are diseased or overrun with pests. Overwatering causes grass blade tips turn yellow and the blades themselves wilt. Underwatering causes grass blades to fade to yellow before turning brown and drying. If you are improperly fertilizing your lawn, then you will see a scorching effect that strips it of its healthy green color.
To address these particular issues, remember to use the recommended amount of fertilizer at the specified time/season. And if you haven’t been careful about watering, be sure to provide your lawn with — depending on the heat — anywhere from a half inch to one-and-a-half inches of water every week during the summer.
At South Austin Irrigation, we’re committed to helping you achieve and maintain more beautiful lawns and gardens. We offer irrigation system sales and repair service as well as expert horticultural advice. For all your landscaping needs, contact us today!