When do I fertilize or apply grub control? There is no one-size-fits-all when it comes to lawn maintenance.
I am often asked to review lawn service contracts or recommend a yearly lawn care schedule. Seasonal projects should be based on stages of growth and potential problems. Whether or not you follow this schedule is up to you and your desired level of maintenance. The following program includes cool season turf, bluegrass and tall fescue.
March to early April: The lawn begins to wake up from its winter slumber. Unfortunately, so do the weeds. Broadleaf weeds like dandelion, henbit and chickweed burst into growth in warmer temperatures.
The ideal time to control these weeds is in the fall. Spring applications should be made on a calm day with temps above 50 degrees. You want a still day because in windy conditions, herbicide sprays drift and damage other landscape plants. Treat only the weeds using spot spraying and when rain is not predicted for at least 24 hours for best results.
Some of us opt not to control spring flowering weeds as they are a primary nectar source for foraging bees.
Crabgrass controls must be applied when the redbud trees fully bloom. To be activated, preventers should be watered into the soil with at least a quarter inch of water. Remember, the best defense from weeds is a thick lawn. Dense stands of grass may not need crabgrass controls.
May: If you water your lawn during the summer, you may want to apply slow-release nitrogen fertilizer. Higher fertility levels during summer heat increase the need for water and decrease overall heat and drought tolerance. If you don’t water the lawn, or minimally water it, skip the fertilizer.
If grubs have been a problem in the past, you may want to apply a product containing imidacloprid or chlorantraniliprole between late May and June. These products work to prevent grub damage. If rainfall does not occur within 24 hours, irrigate with 1/4 inch of water.
Spot-treat summer weeds with liquid or a granular product. If you use a combination product with fertilizer and weed killer, wait 24 hours after the application before watering.
June, July and August: If you have issues with crabgrass and it was a rainy spring, a second application applied by mid-June may be necessary. Dimension (dithiopyr) or Barricade (prodiamine) applied in April typically provide season-long control with a single application.
If you see grub damage and did not treat it earlier, then a grub killer containing Dylox should be applied and watered in within 24 hours of application.
September: Fertilize around Labor Day. This is the most important fertilization of the year. Water in the fertilizer if rainfall does not occur. This is the best time of the year to overseed the lawn to improve the stand.
November: This is the second most crucial time to fertilize. Fertilizer is taken up by the roots but only used in spring. This will result in an early spring green-up. Spray for broadleaf weeds, even if they are small. Broadleaf weeds are much easier to control in the fall than in spring.
Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Have a question for him or other university extension experts? Email them to email@example.com.