Horticulture: May 2005

The spring and summer months are critical to the fertility program for the growth of turfgrass. If you have not fertilized the lawn around your home, shame on you! How can you expect the turfgrass to hold up during the summer months, much less the winter months? A weak stand of turfgrass is an opportunity for a weed community to take over. An example of this situation is weed seeds germinating in weak stands of turfgrass; a better example is weeds growing on bare ground. A strong stand of turfgrass will prevent the weed seeds from germinating properly. It is the time of year to take advantage of the rainy season for those warm-season grasses like bermudagrass, St. Augustine, Zoysiagrass, etc.

Bermudagrass is a commonly used turfgrass in Oklahoma and Texas for residential and commercial lawns because it has good wear and drought resistance and responds positively to nitrogen fertility practices in the spring.

In mid-April to May, the soil temperature begins to rise above 55 degrees F and bermudagrasses begins to break winter dormancy. We can efficiently use the rainfall we receive during the next 60 days to rejuvenate the turfgrasses in the lawn, if we properly fertilize. General fertilizer recommendations are as follows: 1 pound of nitrogen per 1,000 square feet four to five times during the growing season from mid-April to September. This can be accomplished by spreading a balanced fertilizer such as one with an N-P-K ratio of 15-5-10 at the rate of 6 pounds per 1,000 square feet.

If the fertilizer is spread, the mower better be ready and blades better be sharp. The end of the blade (1 ½-inch tip of the mower blade) does the largest amount of the cutting action. This part of the blade must be kept sharp during mowing. It means the difference between slicing the blade of grass as opposed to whacking it off. This damage to the end of the leaf blade can be unsightly and is a point of entry for diseases, which can be the start of the decline of the plant community. When mowing, it is important not to remove more than two-thirds of the leaf blade at one time. Instead, take the cutting height down a level in multiple passes.

Timely application of a fertility program and proper mowing will allow turfgrass to stand out and be enjoyed by your family and guests.