Symptom	Plausible Causes	Suggested Treatment
Blackened Roots	Environment or Disease Necrotic Ringspot
Brown Patches that lift up easily	Pests White grubs (scarab beetle)	Humi-Iron™ Granular Fertilizer
Curled Blades	Environment or Disease Stripe Smut
Dead Blades	Pests White grubs (scarab beetle)
Dead circles or arcs	Human Causes Inadequate watering, lawn scalping, dog urine, fertilizer or pesticide burn Environment or Disease Dollar spot, necrotic ringworm, patch disease, red thread Pests Armyworms, pearl scale, sod webworms
Dead circles surrounded by dark green rings	Human Causes Fertilizer burn Pests Fairy ring, patch disease
Discolored areas	Environment or Disease Patch disease, pink snow mold, pythium blight, red thread, septoria leaf spot, slime mold Pests Leafhoppers
Discolored blades	Environment or Disease Dollar spot, gray snow mold, septoria leaf spot Pests Mites
Disfigured lawn	Pests Ants, gophers, moles, raccoons, skunks
Dry irregular pattern	Environment or Disease Billbug, chinch bug, take all patch
Dry patches in pattern	Human Causes Sprinkler position, fertilizer burn
Dry spots	Human Causes Dog urine burn, gasoline or oil, spill from mower
Froth on blades	Pests Spittlebugs
Mushrooms	Environment or Disease Fairy ring, oak root fungus
Pale green blades	Human Causes Excessive watering Environment or Disease Stripe smut, nitrogen deficiency
Ragged blades	Human Causes Lawn scalping, mechanical injury
Seeding failure	Human Causes Excessive watering, inadequate watering, transplant failure Environment or Disease Damping off Pests Armyworms, birds, cutworms, grasshoppers, millipedes, root maggots, slugs, snails, springtails, voles, wireworms
Split blades	Environment or Disease Stripe Smut
Thinning Lawn	Environment or Disease Iron deficiency, nitrogen deficiency, thatch, too much shade
Webbing and threads	Environment or Disease Dollar spot, pythium blight Pests Sod webworms