My lawn has several large brown patches that appeared over the last few weeks. The rest of the lawn is green. What is causing this and how do I fix it?
Brown patches in an otherwise green lawn can be caused by several things. The timing (appearing over weeks rather than overnight) helps narrow it down. The most likely causes are fungal disease, grub damage, or dog urine spots. Check for fungal disease by looking at the border of the brown area. If you see a darker "smoke ring" of discolored grass at the edges, it is likely Brown Patch fungus, which is very common in warm humid weather. Treat with a fungicide like Scotts DiseaseEx and water only in the morning (never evening) to reduce moisture on the blades overnight. For grub damage, grab a handful of brown grass and tug. If it pulls up easily like a carpet with no roots, grubs have eaten the roots underneath. Peel back the turf and look for white C-shaped larvae. Treat with GrubEx or milky spore. Dog urine creates round brown spots with a ring of extra-green grass around the edge (the nitrogen acts as fertilizer at lower concentrations). The fix is to water the spot heavily immediately after the dog goes. For any cause, once you address the underlying problem, the brown areas will need reseeding. Rake out the dead grass, spread grass seed appropriate for your region, cover lightly with straw, and keep moist until germination in 7-14 days.
Have a similar problem? Ask Tom directly for $3.
Tom Harrison, Certified Master Gardener with 18 years of experience, will provide personalized advice for your specific situation.
Average response time: under 2 minutes · Money-back guarantee
Ask Tom now — $3 →
