Water likely culprit for brown spots

: I have questions on taking care of my lawn. The lawn was planted as sod in March ’07. This was its second winter and I have followed a fairly tight regimen of fertilizer and care. I was very pleased with how it did last summer. The biggest con I have is in repairing urine damage from our dog. The all-fescue grass has browned somewhat in some areas. If this was your lawn, what steps would you take from today until summer to get this lawn healthy and even-looking.

A: I think there are just a few things to cover concerning your lawn. The picture you sent was good enough for me to see some closeups of the grass. I could even spot the locations of your sprinklers.

Fescue is normally brown this time of year if it did not get a fertilizer application around Thanksgiving. The nitrogen applied earlier in the year just runs out of steam and the cold weather turns the grass brown without it.

Fescue lawns do not need to be fertilized as often as some others. Fertilize three times a year: Labor Day, Memorial Day and Thanksgiving. Use a slow-release fertilizer. Manure types are best.

Your grass still has a good, solid stand. There are not a lot of places where the grass is missing. I can see the dog spots since the grass is greener right in those areas.

There is nothing you can do about dog spots as long as the dog can urinate anywhere the dog wants to. You should rake these spots until you see bare ground; seed them with a good-quality tall fescue blend of seed and cover them with about one-eighth of an inch of topdressing or topsoil. Water them daily.

Your lawn is also greener next to the patio and the area between the patio and the wall. The brownest area is in the large part of the lawn, which I think is on the west side. The reason for it browning all over like that is either a lack of fertilizer or water or both. My guess would be water.

The sprinkler heads are probably closer together in the area next to the patio and further apart in the larger areas. This means when the lawn is being irrigated, the area next to the patio is getting more water than the larger area. This may be deceiving to you since you may walk off your patio and the grass near it seems wet; but the large lawn area is not getting enough.

Also, the grass between the patio and the wall is in a different microclimate than the grass in the large area. The large area will get a lot more wind and reflected light, which drives up water use.

If you haven’t already done this, it would be best to put the grass in the large area on a different sprinkler valve than the grass between the patio and wall. If they already are on a different valve, then you may have to increase the number of minutes on the large grass area compared to the patio area. This could be perhaps 20 percent more.

It looks like there is a depression in the grass around the sprinkler heads where someone may use a lawn trimmer to lower the grass around them. This is common when 2-inch popup sprinklers are used instead of the more appropriate 4-inch popup heads. This is true only for tall fescue since it has to be mowed higher than other grasses, a minimum of 2 inches but better at three or more. If you have 2-inch popup sprinkler heads, replace them with 4-inch types. Also, mow your lawn higher, closer to 3 inches.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at morrisr@unce.unr.edu.