03/23/06 Grass Growing

It's grass growing time. I'm Greg Martin with today's Line On Agriculture. This time of year a trip to the local garden or hardware store shows the shelves filled with products designed to give you a lush green lawn. We buy bags of the stuff and dutifully set out to impress our neighbors. A quick look at the instructions for application usually yields the result&if a little is good&a little more can't hurt. Tom Salaiz, research support scientist and turf grass extension specialist with the University of Idaho cautions against over use of fertilizer. SALAIZ: In the spring the turf grass is growing rapidly as it is and it's drawing most of it's growth reserves from stored carbohydrates or stored energy reserves that it stored last fall to get it through the winter. So if you give it excess nitrogen in the spring, it's already growing rapidly and then by giving it an extra excess shot of nitrogen, that will draw too much of those carbohydrate reserves and that would actually cause the turf to go into the summer in a weakened state. Salaiz recommends a half- to three-quarter pound of nitrogen per 1,000 square feet between late March and mid-April, repeated as needed 30-40 days later. He also adds that using a mulching mower is also adding nitrogen. SALAIZ: The grass clippings have nutrients in themselves and as they break down they do release a certain amount of nitrogen and you can actually cut back on the amount of nitrogen you need over a growing season if you do that. It's very difficult to keep up with the rate of growth and so you have to be on top of mowing, very frequently sometimes more than the standard once a week that people follow. Driving down any residential street during the spring and summer you will see a multitude of irrigation systems delivering gallons of water to lawns. Salaiz says that there is a benefit to backing off the water. SALAIZ: It would be very advantages to them from a water savings standpoint in the spring to set their sprinklers to only put out a tenth to fifteen hundreds of an inch of water per day. Whereas in summertime then you can increase the amount of water you are putting back the lawn obviously because the grass is using more water then. And then again in the fall, late August, September, October, when temperatures begin to cool you can set your time back down again. And that would go a long way in saving water as opposed to somebody who just sets their timer for maximum water say for a July setting and then just leaving it there all year long. That's today's Line On Agriculture. I'm Greg Martin on the Northwest Ag Information Network.