Christmas songs play non-stop on the radio, Bing Crosby crooning about snow and white and all those cold things we Arizonans know nothing about, particularly in the last few weeks. Night time temperatures are generally much cooler this time of year with averages in the mid to high 30s. December is usually one of the coldest months in the low desert. Not this year: the 70 degree days and 40 degree nights seem to be here for awhile. Though bad for those dreaming of a white Christmas, it’s perfect for those of us who want an attractive lawn when the relatives come.
The warm weather is ordered and in transit, so there are only a few things left to make the lawn family-picture-perfect. For those who decided not to overseed, the list is even shorter. Non-overseeded bermuda grass requires a minimal amount of water. Dr. Davic Kopec of the University of Arizona Turfgrass Research Center advises homeowners in Phoenix, Tucson, and Yuma to water non-overseeded turf once every few weeks to protect the grass from dehydration. He suggests watering every 21 days, though that is discretionary based on the weather.
Hybrid bermuda overseeded with winter ryegrass requires a little more attention but the visually stunning results are entirely worth the effort. Watering every 3-5 days for 15-20 minutes is sufficient this time of year, though after a good rain you can reduce the frequency slightly. The grass is getting plenty of water if you can penetrate the soil 4-6 inches with a screwdriver or other sharp object.
Since winter growth is slower, mowing once or twice a week is usually adequate. Keep the ryegrass at a height of 3/4 to 1 inch so that the dormant hybrid transitions properly in the spring. If you fertilize, do so every four to six weeks, using a 16-20-0 or similar analysis that is high in phosphorus, which is most commonly found in granular form. Water immediately and thoroughly for a few cycles before mowing again, which will dissolve the fertilizer and prevent it from burning the turf.
Merry Christmas!