Spot treat broadleaf weeds if necessary. This will control spring weeds like dandelions, henbit and chickweed.
Liquid treatments are more effective. Treat during 50-degree or warmer, windless days. Pesticide drift dispersed by wind can damage your and your neighbors’ plants. Rain or irrigation within 24 hours of application will reduce effectiveness.
Are the redbud trees in full bloom? Now is the time to apply crabgrass preventer, which needs to be watered in to work. One-quarter inch of water will be enough to activate any of the commonly available products.
Remember: A good, thick lawn is the best weed prevention.
If you water your lawn regularly all summer then fertilize with a slow-release fertilizer. If your crabgrass control contained a fertilizer, this application may not be necessary.
Additional fertilizers are not needed if you let your lawn go dormant during the heat of summer. Broadleaf weeds can be spot treated with a spray or use a fertilizer that includes a weed killer. Rain or irrigation within 24 hours of application will reduce the effectiveness of the weed killer, but the fertilizer needs to be watered in.
For best weed control, wait 24 hours after the application before watering if the product is a combination of fertilizer and herbicide.
June through mid-July
A heavy crabgrass infestation may require a follow-up application. If necessary, apply a second round of crabgrass preventer in early June.
Only one application is needed if you applied Dimension (dithiopyr) or Barricade (prodiamine) in the spring. These two products usually provide season-long control with a single application. Remember to water it in.
If grubs have been a problem in the past, apply a product containing imidacloprid during the first half of July. This works to prevent grub damage. It also must be watered in to activate.
Fertilize around Labor Day — the most important fertilization of the year.
Water in the fertilizer for best results and use a high nitrogen source. This is also the ideal time to overseed a bluegrass or tall fescue lawn.
Fertilize the lawn. This is the second most important time. This fertilizer is taken up by the roots but is not used until the following spring. Water in fertilizer.
Spray for broadleaf weeds even if they are small. They are much easier to control in the fall than in the spring. Spray on a day that is at least 50 degrees. Rain or irrigation within 24 hours reduces effectiveness. Use label rates for all products.
That’s it. As you can see, it is not that complicated once you know the proper timing and practice. Following these guidelines will have you on your way to a healthy and happy lawn.
Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Got a question for him or other university extension experts? Email them to firstname.lastname@example.org.