The best way to counteract weeds in an all-natural organic turf care program is to get grass growing. Soil temps, germination time frames, and pH all affect growing healthy grass. In the Northeast, the window to over-seed caps by the end of May. Therefore, the approach we take to over-seeding this spring is different than it is in the fall.
On residential properties, the goal is to establish turf coverage anywhere you have bare soil through topdressing and over-seeding. The simplest approach is to incorporate the grass seed and a loam/compost mix in a wheelbarrow and then use the mixture to make your repairs. A seed slicer is a great alternative to core aeration for spring overseeding. Seed slicers cut small slits into the soil, and then deposit grass seed into the cut rows. They provide great seed-to-soil contact to help with germination, minimize soil disruption, and reduce the risk of exposing weed seeds in your lawns. It’s important to note that seed slicing does not address compaction, and lawns should still be aerated and overseeded in the fall.
On athletic fields, we generally aerate if the field is compacted, and broadcast the seed at a heavy rate. If turf conditions are really poor—especially around the goal mouths on high traffic sports fields—you may need to do additional remediation.
Whether dealing with residential or athletic fields, the goal is to get coverage as quickly as possible in the spring: quick coverage helps suppress weeds. Therefore, we do not recommend the use of grass seed blends that contain Kentucky bluegrass, as it takes too long to germinate. The spring overseeding window to establish grass can be very short, so we recommend using a TriRye grass seed—known for quick germination—before May 15th. Since it can take up to 18 months for grass to become fully established from seed, anticipate some die off from spring over-seeding as you enter the heat of the summer.
Remember: the goal is to promote quick coverage to help suppress weeds and now’s the time to do it!