The answer to this will depend on what is causing the brown spots. Brown spots in your lawn could be from something as simple as a female dog peeing on your lawn or it might be one of several fungal diseases…without seeing it, it would be impossible to diagnose. In the case of a dog being the problem you’ll have to prevent the dog from peeing on the lawn. If this is impossible then keep an eye on the dog and, once it finishes peeing, hose down the area with at least a couple of gallons of water. This will dilute the urine to the point that it won’t burn the grass plants. As far as brown spot caused by diseases, you’ll need to first identify the disease. Here’s a good site to help with that: http://www.american-lawns.com/problems/sick_lawns.html You should also bring a sample of the brown patch into Hewitt’s and let one of our experts identify it and the proper solution…usually a high nitrogen lawn food or a fungicide. Make sure the sample includes the transition zone from healthy grass into the diseases area. The folks that usually have an issue with fungal lawn diseases are folks that have an underground sprinkling system that is set up to run for a short time each day. A damp lawn is the perfect breeding ground for fungal disease. Your sprinkling system should be set up to provide 1″ of water per week all at once. This will soak the soil at least 8″ deep promoting a stronger, deeper root system. This also allows the lawn to enjoy extended periods of dryness which makes it far less likely that a fungal disease will be able to take hold. To figure out how long a sprinkler zone takes to put out 1″ of water, place a small tuna fish or cat food can within the zone and let it run until the can is full. Then reset the system to run that zone just once a week for as long as it took to fill the tuna fish can. Do the same for all the zones and your lawn will be better for it and you’ll use way less water and save money on fungicides too.