I can’t get my lawn to grow and have noticed that moisture doesn’t soak in when I water it. What can I do?
If water is running off the lawn without soaking in, you’ll need to aerate it. If you have a large area, consider renting a power aerator from The Home Depot Tool Rental Center. Aeration will remove 1–3-inch plugs from the lawn. Leave the plugs on the lawn; they’ll dissolve in the water from rain or sprinklers.

After aerating, spread a thin layer of compost over the area and water it in well. The compost plus the soil from the plugs will work their way down into the holes. You can then overseed your entire lawn. Aerating should improve the soil beneath the lawn and help the grass grow lush and thick, which will help keep weeds at bay.  

What’s the right way to prepare soil before laying sod?
When you prepare soil for a lawn, your main goal is to provide a good environment for developing deep-rooted grass plants. The faster and deeper the roots can grow, the better your chance of success with the sod. Roots grow best in a loose organic soil that’s evenly moist but not soaking wet.

You’ll need to loosen the soil as deeply as possible, add organic matter such as compost, possibly add amendments such as lime or fertilizer, then smooth the soil and rake the surface to a fine texture. The proportions of organic matter and amendments depend on the native soil, so run a soil test and work according to the results.  

How can I treat established grass that has been damaged by dog urine?
Dog urine contains a concentration of salts, so it has probably thrown off the soil pH a little. Try raking about 1 inch of compost into the area. The compost contains soil organisms that can help balance the soil’s biology and chemistry. Depending on the grass species, new blades may sprout in the renovated area, and you can always put down some seed to try to jump-start it even more.

If your dog uses your lawn for relief, douse the area with a hose as soon as you can to dilute the effect of the urine. You could try to train your dog to go in 1 specific area so most of your lawn stays nice and green.  

I have brown spot fungus on my lawn. How do I treat it and what kind of products should I use to get rid of it?
There are several products specifically formulated to control brown patches from brands such as Spectracide and Bayer, available in-store. Choose whichever is locally available and apply according to the label directions.

The best way to prevent brown patches on your lawn is to follow good lawn-care practices. This can be very effective and is much easier and less expensive than using fungicides.

Avoid high rates of nitrogen fertilizer on cool-season grasses in the late spring and summer and on warm-season grasses in mid- to late fall. Irrigate grass only when needed to a depth of 4–6 inches. Water in the early morning; this disease can spread quickly when free moisture is present. Remove clippings to avoid spreading the disease to other areas. Keep lawns mowed on a regular basis to the proper height for the grass species you are growing. Prevent excessive thatch buildup. Provide good drainage for both surface and subsurface areas.  

My lawn has a yellow patch that I’ve been trying to get rid of for 2 years. I tried using lime but it was a temporary solution. What do you suggest?
Lime will change the soil’s pH. If it’s very acidic, lime will sweeten it and perhaps make a more welcoming place for the turf grass. However, the underlying cause may or may not be soil pH. A more permanent solution is to dig up the yellowing area to remove the grass, the grass roots and a few inches of soil. Replace the soil with some from another part of the garden, reseed and keep it watered. New grass will sprout in 7–10 days and grow lush and thick. This should take care of the problem once and for all.  

I have a lot of thatch. Should I still leave grass clippings on this type of grass?
Thatch is a buildup of dead stolons or rhizomes. If the layer is thick enough, it can prevent water and fertilizer from penetrating the soil. Dethatching can remove most of the debris. Grass clippings can contribute to thatch, but generally they decompose to almost nothing once the moisture evaporates. If you don’t plan to dethatch your lawn any time soon, you should bag your clippings. If you do dethatch, you can keep leaving the clippings on the lawn.  

Is it dangerous to apply pest-control products to our lawn shortly before or after applying fertilizer?
A grub killer applied in conjunction with fertilizer won’t cause problems for your turf. If your lawn was burned after the fertilizer application, it’s most likely because the application was too heavy or wasn’t watered in correctly. For best results, feed your lawn in spring and fall when the air is cooler and the sun is less intense.  

How can I kill the creeping Bermuda grass that’s in my fescue lawn?
Bermuda grass is often used to overseed fescue so the lawn will stay green all year long. There’s no product that will kill the Bermuda grass without harming your fescue lawn, but if you dig out the Bermuda you can apply a pre-emergent herbicide to keep new Bermuda grass seeds from sprouting. A wide selection of herbicides from brands such as Ortho, Spectracide and Roundup are available at your local The Home Depot.  

How can I control the lawn moss that is damaging my turf?
Moss is usually a symptom of several problems, including compacted and acidic soil, poor drainage and too much shade.

To repair your lawn, begin by using a Vigoro fertilizer in fall and again in spring, applying 1 pound of actual nitrogen per 1,000 square feet of lawn. Remove the moss by raking and reseeding the affected areas on your lawn. If your grass is healthy, it will crowd out any future moss. If you haven’t aerated, consider doing so this spring using a core aerator, which can be rented from The Home Depot Tool Rental Center. Spread a thin layer of sand over the lawn and allow the plugs to dissolve after a healthy watering. The sand and soil from the plugs will work their way into the holes left by the aerator, reducing compaction and giving excess moisture a way to escape.  

I read in your Q&A that grass clippings add nitrogen to composts. My mower is a mow/mulch that finely cuts the grass each time I mow. Is this sufficient nitrogen for my grass ?
Your mulching mower will do an adequate job of cutting the grass clippings into small enough pieces that they will help nourish your turf. You'll probably need to add a supplemental source of nitrogen during the growing season to keep your lawn lush and green. If it begins to yellow, it needs a dose of fertilizer. If it remains thick and green all summer long, you won't need to fertilize.