Spring bulbs are blooming, trees are budding and the grass has started to turn green.
With everything returning to life, it's time to "do" gardening instead of "think" gardening. The longer days and mild temperatures mean cool-season lawn grasses (Kentucky bluegrass, fescue and ryegrass) need attention. With proper timing and technique, your lawn could become the envy of the neighborhood.
Here are tips to help you plan your spring lawn-care program this gardening season:
Broadleaf weeds will start to outgrow the lawn. Prevent them by spot-treating with a liquid broadleaf weedkiller. Avoid using "weed and feed" type granular products at this time. The weedkiller is good, but the fertilizer is not. Likewise, broadcast spreading weedkiller over the entire lawn to control a few weeds wastes resources and is not good for the environment. Also, avoid using weedkillers that contain the chemical chlopyralid. Grass clippings from treated lawns can contaminate municipal composting facilities such as the one in Lawrence.
Instead, use products containing 2,4-D, MCPP, Dicamba, carfentrazone, or Trimec Treat when the temperatures are 50 degrees or warmer and the winds are less than 5 mph. Rain or irrigation within 24 hours of application will reduce effectiveness.
Similarly, apply crabgrass preventer when redbud trees are in full bloom. For best results, the pre-emergence herbicide needs to be applied and watered in at least two weeks prior to the seeds germinating. Avoid using products containing fertilizers because it is too early for lawn food.
Fertilize with slow-release fertilizer at the rate of one pound of nitrogen per 1,000 square feet of turf. To calculate this rate, divide 100 by the first number of the three-number analysis on the bag. The result is the number of pounds of fertilizer you should apply to 1,000 square feet of lawn. If there are broadleaf weeds, you can spot-treat with a spray or use a fertilizer that includes a weedkiller. Rain or irrigation within 24 hours of application will reduce effectiveness of the weedkiller, but the fertilizer needs to be watered in. If you are using a product that has both fertilizer and weedkiller, wait 24 hours after the application before watering.
Make a second application of crabgrass preventer by June 15 unless you used Dimension or Barricade, which normally provide season-long control and don't need to be applied again. If grubs have been a problem in the past, apply grub killers containing "Merit" or "Mach 2" during the first half of July. These work as a preventive and must be watered in to be activated.
- Bruce Chladny is horticulture agent at K-State Research and Extension-Douglas County. For more information, call him at 843-7058 from 8 a.m. to 5 p.m. weekdays.