2torial #0834:
Learn2 Reseed a Lawn (continued)

Diagnose the problem

If your lawn's problem is too many weeds, skip to Step 2 to eliminate the weeds and begin preparing the ground for new seed. If you have brown spots or an entirely brown lawn, keep reading to diagnose the problem. Once you know what went wrong, you can prevent it from happening again.

Not enough water? Underwatering or uneven watering can kill all the grass or kill it in spots. How much you need to water depends upon your climate and soil type. For a complete guide, see 2torial #0550: Water Your Lawn.

Uneven ground that collects water? If water immediately runs off your lawn or gathers in puddles, you'll need to regrade all or parts of it to prevent further drowned or brown spots. Grading can be as simple as knocking down high spots with a shovel to even them out, or it may involve buying topsoil to fill low areas. Grade these areas before you prepare the ground for reseeding.

Too much thatch? Thatch is the collection of grass cuttings and old roots at the base of the grass blades. It's also where fungus and bugs hide. If it's 1/2 inch (1.25 centimeters) thick or more, it needs to be removed so that fertilizer and water can enter the soil. To remove it, use a rake, rent a dethatcher from an equipment rental company, or purchase a dethatching attachment for your lawnmower.

Insects bugging you? If insects are causing damage, you'll find them around the edges of your brown spots, munching fresh grass. One clue that this may be the culprit is if you notice more birds than usual on your lawn.

Put a sample insect in a jar and take it to your local nursery. They'll identify both the insect and the best way to get rid of it, preferably organically.

Too much fertilizer? If spread unevenly, fertilizer can burn the grass in areas where the fertilizer is concentrated. Time's the only cure for this problem, and you'll have to wait for the fertilizer to wear away.

Problems with dogs? Dog urine has a slightly alkaline content that can burn brown spots into your lawn. You may need to keep your dog off the lawn, or train it to relieve itself elsewhere. If neighbor dogs are causing the problem, ask your neighbors to curb their dogs, or put up a fence.

A fungus among us? Fungus can be difficult to diagnose, but it may be the problem if you've ruled out all other possibilities. Talk to the experts at your local nursery and see if they recommend a fungicide. If you think it will help, bring a sample for diagnosis.