When repairing or renovating lawns, specialized equipment can increase effectiveness and make the job much easier. Match equipment to the task that needs to be done for best results.
As mentioned already, core aerification is an important and highly overseeding lawn practice for many lawns. This process is useful to help reduce soil compaction and thatch, improve surface drainage, and improve conditions prior to overseeding. Core aerifiers insert hollow tines into the lawn and pull out plugs of soil. Size of cores removed will depend on the machine used, soil moisture, and type of soil. Core spacing also varies with the specific machine being used. Machines can be rented or aerifying services are available for hire.
Vertical mowers have rotating blades arranged vertically that can cut into turf and soil. These machines can be used to remove thatch (dethatching). Turfgrass rooting in the thatch is typically torn out, so reseeding is suggested afterwards. Vertical mowers can also roughen the soil prior to overseeding areas.
Slit-seeders are useful for lawn renovation projects. Slit-seeders combine vertical mowing with seeding. As the machine goes across the lawn, it opens the soil and deposits seed directly into the soil opening. Most slit-seeders have a roller that helps firm the soil after seeding. Seed is metered at a predetermined rate; it’s suggested to apply half the desired seeding rate in one direction and the other half on a second pass perpendicular to the first.
Since the seed is placed in direct contact with the soil, seeding success is usually high when using slit-seeders. In addition, existing grass and debris does not need to be completely removed prior to the overseeding process. Timing should be the same as for conventional lawn seeding, which ideally would be late August into early September. Many rental agencies carry slit-seeders or many lawn and landscape services can do it for hire.