Aerating your lawn is a great way to reduce thatch, loosen up compacted soils and make it easier for water and nutrients to reach the roots of your turf.
Even with the best care available, lawns can thin out and lose color due to excessive thatch buildup, hard or compacted soils, or periods of high temperature, high humidity, or drought. Aerifying and overseeding is recognized by turf experts such as golf course superintendents as the best treatment to control thatch, reduce compaction, fill-in bare spots and revitalize growth.
An aeration treatment removes small cores of soil and thatch to allow air, moisture and fertilizer to penetrate down to the root zone. The cores brought to the surface contain microorganisms, which help the breakdown of the woody thatch tissue. This allows the roots of existing grass plants to spread out and grow deeper, creating a healthier, thicker lawn.
Overseeding in cool-season areas will fill-in bare or thin spots and help build a thicker lawn faster. The new seed quickly takes root in the freshly aerated lawn and provides new life to your already established grass. As your lawn gets thicker and healthier, your new grass plants help reduce the chance of new weeds sprouting.
Aeration can be done anytime the lawn is actively growing. In the south, the preferred season is late spring. In the north, early fall.
While aeration is beneficial for many lawns, it isn't appropriate for every situation. Here are come guides to determine if your lawn needs this service:
When the soil is compacted
When the thatch layer is more than 1" thick
If you're going to overseed your lawn. Aeration exposes soil and provides better seed-to-soil contact needed for good seed establishment.
Yes, but usually only for excess thatch buildup. Sandy soils don't become compacted and rarely need aerated. If thatch is a problem, there is different aeration machinery to be used. Instead of using a machine that pulls out plugs of soil, use equipment that pierces the soil with a sharp spike. This type of equipment is not recommended for heavy, clay type soils as it further compacts the clay.
Soil temperature is the best indication of when to aerate. Studies have shown that for cool season grasses in particular, soil temperatures in the 50 — 65 degree range is the ideal time to aerate a lawn. It is when temperatures are in this range that grass roots can grow as much as 1" a week. Aggressive core aeration will promote healthy root development by providing an oxygen-rich environment, plus it allows more water into the soil at an important time in the roots development cycle.