Should I aerate my lawn?
We put tall fescue sod down in the fall of 2018. It has not fared well, and about 40% is now exposed soil. Two overseeding attempts last fall were unsuccessful (in part, at least, because many seeds were washed away by biblical deluges). I plan to overseed again this spring. How can I judge whether the ground needs core aeration? Thank you Steve
Benton County Oregon
Hello. In general, if your soil is compacted by heavy foot traffic and or machinery yes aeration could help alleviate compaction. I have loads of questions to be able to answer this question thoroughly. First was the sod installation a lawn renovation or a new lawn installation? What time of year was it installed? Was the ground properly prepared prior to the sod installation? How much sunlight does the yard get? Did you apply fertilizer at the 4-6 week time period? Finally, was it kept moist? Ditto for the over-seeding attempts. Optimum temperatures for seeding lawns are 60 to 85 degrees. (Mid-August to Mid-September around here.) It requires proper preparation of the soil, selecting the proper seed mix for the location, sun exposure, and constant light moisture. Drying in between irrigation or rain showers does not make for good germination. I have included a link below about establishment or restoration of a lawn using seed or sod. This OSU Extension publication goes through all the steps required to prepare your soil for either type of grass installation. The soil preparation is basically the same for both types of grass installation and is important for success.
Practical Lawn Establishment and Renovation https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1550.pdf
I have also included a comprehensive guide to lawn maintenance and the different approaches that can be taken. Basically mowing, irrigating, fertilizing. How often, how much and what grass requires to be healthy and thick. I hope that this information
Practical Lawn Care for Western Oregon https://catalog.extension.oregonstate.edu/ec1521/html
*First was the sod installation a lawn renovation or a new lawn installation?
The sod was laid in October 2018. It was a new installation after the backyard was completely destroyed and remade, with the addition of low walls, a patio, and a paver walkway.
Hello again. Your plan has a couple things that may need to be revisited. The first is the recommended use of a dethatcher in the lawn renovation portion of the first document in my first note. Not only does this machine remove unwanted lawn materials it will help to break up the soil and once the debris is raked up will provide a decent bed for the new seed. You could possibly skip the step of putting down soil before seeding. You mention the tough removal of acorns, to me that infers shade.
While tall fescue is shade tolerant in Western Oregon it prefers hot dry areas. It has disease issues in Western Oregon. You may do better with a mixture of seeds since your area is part sun and part shade. Call a local grass seed company (not a big box store) and discuss their available seeds to match your yard’s conditions. Keep in mind that after several years your yard will have many varieties of grass in it unless you work very hard to maintain a single variety and therefore color. If you are worried about matching the sod that survived, then try tall fescue again. Keep in mind that it did not seem to do well at your location.
My meat thermometer temperature range starts at 100 degrees. You can purchase a soil thermometer locally for around $10-15. It is easy to use and made for the task at hand. As temperature and moisture are the two keys needed for good grass seed germination find one to check your soil temperature. Shady areas of you yard will most likely remain cooler longer.
I recommend that you explore the hydro mulch option. The seed is mixed with a coating of mulching material and is sprayed on wet. The mulch protects it from drying too much in between watering sessions. Hydro mulch would solve the problem of putting down a thin soil/compost layer over the newly deposited seed. I say this as a 1/8th inch layer of anything is very hard to get right. hydro mulch fixes the issue. Good luck with your project!