Click below to listen to my Garden Bite radio show: Spring lawn care
Ahhhh, the first full week of May and I have had lots of questions about lawns! I know how anxious many folks are to get at their lawns but, really, the best time to seed, sod, fertilize, aerate and dethatch is August into September in cooler climates. That said…. here’s what you can do now
You have about a week to apply a pre-emergent for crabgrass, in mid-May it’s time for a post-emergent for crabgrass. Weed control in lawns and turf [U of MN]
From May to early June, you can apply a broadleaf herbicide. The best time is September through October but I know you’re anxious!
You can apply a fertilizer now through early June. You do NOT want to fertilize during hot, dry weather.
You can seed your lawn now – but always make sure you have good seed to soil contact. Just throwing seed on top of grass is a waste of time and seed! That means you have to rake out the dead stuff, put the proper seed down for your sun/shade conditions and then keep the area moist while the seeds sprout. Again, the best time to do this is late August into September.
dog pee spots
My own lawn is in need of dethatching. The best time is mid-August through September but you have a 2 week window right now to perform this task. Dethatching is necessary when that brown, fibrous mat that’s between the soil surface and where the grass shoots start to turn green is about ¾ of an inch thick. To find out how thick your thatch is cut a small, pie shaped wedge out of the lawn and measure. Getting rid of thatch is best done with a power rake you’ll find at most rental places. The thatch can then be composted or even used as a mulch.
You also have till the end of May to aerate your lawn. Aerating removes small cores of soil from your lawn and helps relieve soil compaction and improve drainage, water infiltration, and oxygen levels. Again, this is best done mechanically with a core aerifier machine.
core aerator soil chunks
This is a comprehensive article on Lawn Renovation from the University of MN Extension.