Fall Lawn Care Tips
Late summer is the preferred time to undertake lawn renovation projects. This would include over-seeding existing turf or replacing problem areas with sod or re-seeding. As a general guideline, if problem areas or more than 50% weeds or undesired turf, then replacement is recommended. If there is still over 50% desirable turf, then over-seeding and selective weed control could bring the lawn back into good condition.
Areas to be replaced should first be cleared of existing growth with a non-selective herbicide or by physically removing the layer of turf and weeds; a sod-cutter can aid in the removal. After the herbicide does its work, seeding may be accomplished using a mechanical slice-seeder (= slit-seeder), or by first using a cultivator to till the dead organic matter into the soil and then using a seed spreader to broadcast the seed. Whether or not to cultivate depends on a number of factors including whether or not there is a thick thatch layer that will interfere with seed-to-soil contact and seedling establishment. A thatch layer that’s greater than 3/4″ thick should be removed. Maximum germination of turfgrass seed occurs when the seed is in direct contact with the soil but still exposed to sunlight.
Over-seeding thin turf takes less preparation and involves spreading new turf seed over the top of existing thin turf. As long as there is good seed-to-soil contact, over-seeding can be very successful. Seed-to-soil contact is critical for the overall success of re-seeding.
Turf renovation should also include soil testing to assure the nutritional health of the new grass plants. Also, seeding should be finished by late September to give the young turf plenty of time to get established before winter.