For cool season grasses like Kentucky bluegrass and tall fescue, spring is an excellent time of year. They love the cool spring temperatures and put on significant root growth during April and May, which will help your lawn tolerate our next hot, dry Nebraska summer. Here are a few techniques you can use to get your lawn off to a good start this spring:
* Fertilization. Maintained at their highest level, home lawns of Kentucky bluegrass receive up to four fertilizer applications during the growing season. However, Kentucky bluegrass and turf-type tall fescue lawns can be maintained at a lower level, with fewer fertilizer applications, and still result in a beautiful lawn. Fewer applications of nitrogen fertilizer will result in a cost savings for the homeowner, better turfgrass stress tolerance, slower shoot growth and less mowing. So before purchasing your fertilizer products this spring, decide what is most appropriate for your lawn and your wallet.
If you plan to reduce the amount of fertilizer you apply to your lawn, then one application of fertilizer in April & May, instead of two, would be a great place to start. Apply the traditional first fertilizer application of spring between April 20th and May 10th, using a product containing slow release fertilizer sources like urea formaldehyde, sulfur-coated urea and IBDU whenever possible. These fertilizer ingredients will be listed on the product bag under "nitrogen source".
Skip the second spring fertilizer application, which is applied around May 30th, and is usually a combination fertilizer and broadleaf weed control. Spot sprays of liquid herbicide are more efficient and cost-effective at controlling broadleaf weeds like dandelions than a broadcast granular application, anyway.
* Weed Control. The first fertilizer application of the season is usually a combination fertilizer and pre-emergent herbicide. Several pre-emergent herbicide products provide good weed control; look for these chemical names under the active ingredient on the fertilizer bag: balan (Benefin -- 6 weeks), dithiopyr (Dimension -- 9 weeks), pendimethalin (12 weeks), prodiamine (Barricade -- 16 weeks) or Team (combination of trifluralin and benefin -- 8 weeks). Remember, each pre-emergence herbicide has a specific length of residual control. Two or more applications are often necessary to give season-long weed control.
* Mowing. Kentucky bluegrass and tall fescue should be mowed at a height of 2½-3 inches. This taller cutting height encourages deep root development, which will enable your lawn to draw water from a larger area and give the turf more tolerance for hot summer temperatures. Mow your lawn frequently enough that you remove no more than one-third of the grass height at each mowing.
* Bagging vs. Mulching. Ideally, mowing is done frequently enough that clippings can be left on the lawn. Clippings returned to the turf can contribute up to 1 lb. Nitrogen per 1,000 sq.ft. over the course of a summer and can replace one additional fertilizer application.
Returning clippings to the lawn will not contribute to thatch development, unless you are removing more than one-third of the grass height at each mowing. Heavy clippings, if left on the lawn, will cause damage through light exclusion, resulting in yellowing and thinning of the turf and may encourage disease problems. Heavy clippings can be bagged and put out for city recycling, added to your compost pile or used as mulch in your landscape.