Why Is My Grass Turning White? A Complete Guide
Fix your white grass and move on to greener pastures
Highlights
Fungus like powdery mildew can cause grass to turn white.
Applying too much fertilizer can cause grass to turn white.
Stress can cause grass to turn white.
If you notice white patches on your grass or if your whole lawn is affected, you’re likely wondering why your grass is turning white. Grass can turn white because of too much moisture, not enough moisture, or too much fertilizer. Luckily, there are some steps to take to prevent your grass from going white and restore damaged areas. Whether you decide to hire a local lawn care pro or use a DIY solution, here are the top three causes of white grass and how to fix them.
1. Powdery Mildew
If your white-colored grass has a dusty, grayish appearance, your culprit is likely powdery mildew. This fungus thrives in areas with obstructed sunlight, where moisture might linger. Don’t confuse this fungus with snow mold, which has a similar coloring but appears as webbing in the grass. Since powdery mildew spreads by spores, it can easily occur in any area of your lawn with good growing conditions, but luckily it’s not particularly invasive.
How to Prevent Powdery Mildew
To prevent powdery mildew, ensure your lawn gets as much direct sunlight as possible. Prune trees and shrubs back to allow as much sunlight as possible. You can also choose to plant grasses that are more shade tolerant and less susceptible to powdery mildew, such as fine fescues and shade-resistant bluegrasses, in areas of your yard that are shadier and damper.
How to Control Powdery Mildew
If you have a powdery mildew problem in your grass, avoid mowing the affected area until it recovers to avoid spreading the fungus to other parts of your lawn. Ensure your lawn has ample drainage to allow the area to dry out thoroughly. When you water your lawn, make sure to water for a longer period of time but less frequently, about once every three days, rather than light, daily watering. This will improve your grass’ root health and limit the spread of powdery mildew.
2. Overfertilization
If you have recently fertilized your lawn, chances are that the white coloring on the grass blades is residue from too much fertilizer. This type of white grass will look like it has a crusty build-up, which is caused by fertilizer granules dissolving with water and redepositing on the grass in crystalized form.
To resolve the results of overfertilization, clean up any chunks of fertilizer and then water your grass heavily until water stops soaking into the soil. Avoid mowing for a few days while the grass recovers, and if needed, aerate your lawn to reduce surface moisture and stimulate root growth.
3. Stressed or Sick Grass
Your white or grayish grass could be the result of stress to the plants. This situation is likely the result of mowing your grass too short, very hot and dry weather, or other adverse conditions. To help resolve this scenario, make sure to aerate your lawn, water deeply, and avoid cutting more than one-third of the height of the grass blades. These steps will help stressed grass recover and return to its normal, green color. For help restoring grass to its natural state, consider hiring a lawn treatment professional to resolve issues from powdery mildew, overfertilization, or sick grass.
Frequently Asked Questions
You can use a fungicide to help control powdery mildew, but you should apply it judiciously as it can damage soil health and persist in the soil. Most of the time, proper watering, surface drying, and limiting shade can control powdery mildew without needing harsher interventions. If you have a repeated problem with powdery mildew, you can also try planting a shade-resistant type of grass that will be less susceptible to the fungus.
If you apply too much fertilizer to your grass, it can take about three weeks to recover. If you still have dead patches after three weeks, it might be time to remove the dead grass and overseed the affected area. Since overfertilizing can also cause problems with fungus, leading to further damage to the grass, monitor your grass color and growth for one month after over fertilizing.
If your grass is stressed from being over-trimmed, try watering it heavily and then allowing it to recover for at least two weeks before mowing again. If you notice brown patches where the grass has died off because it’s too short, you should remove the dead grass and overseed the area. Leaving dead patches can invite weeds and other problems, so if you want a totally green lawn, getting rid of dead patches should include removing the dead sections before reseeding the area.