May is a great month to help your lawn move forward by aerating and seeding it afterward, often called overseeding. This is normally a great time to aerate because the moisture content in the soil is high, allowing wonderful plugs to be removed by the assistance of deeper penetration by the machine. Dry, compacted soil is very difficult to aerate even with professional grade equipment. While you can rent small aerators, they are not the same in terms of weight, width, and tine health (length of the steel hollow spikes). I maintain new tines on our machines that are key in breaking up the soil by removing 1″ diameter plug up to 3-4″ in depth. Why aerate?
Benefits of Aeration.
- Increases moisture penetration
- Enhances oxygen exchange (important for healthy roots)
- Reduces soil compaction (especially soils high in clay)
- Facilitates penetration of fertilizers and other lawn products
- Increases rate of thatch decomposition
- Enhances root development
While power raking or dethatching is a process reserved for lawns with excessive thatch (1″) or more, you can overseed a lawn after aerating because of the holes created. Aeration is also a form of dethatching. Overseeding is done by using specific seed types for the lawn location and occurs by spreading the seed out over the entire lawn using a spreader. The seed falls in the new holes and therefore makes great seed to soil contact, a necessary environment for good results. Care needs to be taken when edging along mulch beds, walkways, and gravel driveways because the seed will grow and then becomes a weeding issue! Some of the seed falls onto the plugs and ground which may also germinate,although this is not the main expectation. Overseeding introduces new, superior turf into an existing lawn, especially thin and weak ones. Overseeding can also assist in repairing damaged lawns if there are several passes to tear up the area or if topsoil is applied before applying the seed. Again, the seed to soil contact is important. Surprisingly, grass can grow in many soil types which you may not think possible. The key here is picking out the correct grass type, seeding at the right time, and using the proper equipment. May is normally ideal due to cool days and nights, yet the soil has warmed up enough to faciliate good seed germination.
Most lawns can benefit from annual aeration, be it in the spring or fall, while overseeding is left for improving existing turf in weak lawns or lawns needing increased density. Of course, the next step is to get onto a good fertilizer and turf health care program to maximize the results as aftercare. Treatments may include sea kelp to enhance the soil quality and a high calcium lime to improve seed germination/soil structure/and soil pH.
Aeration can be done as an annual process to help keep thatch in check and to prepare for overseeding. While you can aerate and not overseed, you cannot overseed onto undisturbed ground without aerating first (unless new loam has been applied). With such a short growing season, it really makes sense to consider one or both of these treatments if you want to move your lawn forward and receive the rewards of maximum results. If you don’t want to do it yourself, find a local company like ours and have it done for you. Most lawn care companies will provide a free estimate and recommend the grass varieties to be used at your location. Good luck and may you achieve the lawn of your dreams this year!