Are you asking yourself if it is time to rent a rototiller and start over on your lawn? That's certainly one way to tackle a yard that's been abused, but it isn't the only way. Unless the yard is really bumpy and uneven, the rototiller just isn't necessary. In fact, tilling just brings up more weed seeds to be exposed to sunlight and germinate. There are 4 simple things that you can do to restore a neglected patchy lawn, rather than re-sodding.
1. Top-dress! Raking a thin layer of compost over the surface of your lawn will dramatically change the way your lawn looks and feels. Here's why. The compost allows any accumulated thatch to quickly decompose. It also allows more irrigation water to be retained, so you will use less water. Your lawn will be more resistant to wear from foot traffic and pets. Also, you're lawn will benefit from the nutrients contained in the compost. When people have come into the nursery complaining about how poor their lawn is. I have usually sold them a bag of compost and told them to rake it over the worst spots. They almost always come back to get more!
2. Mow higher and leave the clippings! Most lawns are mowed too low. I recommend gradually moving the deck up one notch each week, until you are at the maximum height setting and then maintain that height until fall. Leaving longer blades of grass allows the turf to be more efficient. Remember, all the food is manufactured by the leaf, and when we cut too low we limit the turf's ability to manufacture food. Some folks believe leaving the clippings creates thatch, but in reality thatch is just dead crown material with a fairly high cellulose content. The grass blades are mostly water, carbon dioxide, and some nitrogen, which need to be recycled back into the turf.
3. Water properly! Healthy turf roots extend down about 8 inches, so we need to apply water to penetrate to that depth. After your sprinkler is run, slice the turf with a shovel to see how far the water penetrated. You may have to adjust the length of time that the sprinkler has been running to achieve this maximum depth. On soils with a high clay content or that are on a slope you may have to use a technique called spray soak. Spray soaking is where you program the controller with multiple start times. You are still applying the same amount of water, but watering in 10 to 25 minute bursts per station, so that water has a chance to soak in.
4. Fertilize! Compost gets the turf off to a great start, but after 8-10 weeks you will need to feed the lawn again. Remember to feed at a 4/1/1 ration. 4 parts nitrogen, 1 part phosphorous, 1 part potassium. Fertilizers that contain iron and sulfur are beneficial in our soils where we have an abundance of calcium carbonate.
Some years ago, I looked at a lawn and I couldn't find one single blade of bluegrass. The lawn appeared to be 100% Johnson (Quack grass). The homeowner just didn't want to spend the time or money to start over, so I had them raise the deck of their lawn mower up, put them on a proper watering schedule, top-dress the really bad spots and begin fertilizing. I was called back 2 years later and I could not find any quack grass. The lawn looked perfect! I asked the homeowner if they'd planted any bluegrass seed. They insisted they had not. Give this a try and let us know how it works!