Fall Turf Management
Fall Maintenance and Improvements to Turf Grasses
Fall is a great time to evaluate turf, make improvements, and apply fertilizer. The University of Nebraska – Lincoln turf grass team recommends applying a fertilizer at 1 pound nitrogen per 1000 square ft. now, and again in 4-6 weeks or at least mowing while the turf is still green. Mid-September to Late-October is also a good time to apply broadleaf herbicides to stay ahead of dandelions and other winter annual broadleaf weeds that try to establish while the turf is dormant and less actively growing.
This is also a good time to enhance turf density with over-seeding or starting over with new seeding if using cool season grasses such as Turf Type Tall Fescue or Kentucky Blue Grass. If the turf is just a little thin or has small thin patches, over-seeding can be very effective. Soil preparaton is the most critical part of seeding. The first step is to reduce mowing height to 1-1.5 inches to reduce competition for new seed from the established turf. This allows sunlight to reach the new seedlings and seed to reach the soil for better contact. Aerate with the largest tines possible aiming for 20-40 holes per square foot. Be sure to clean additional thatch with a power raking or similar process.
Next, apply a starter fertilizer that is high in phosphorus and follow with seed. Apply seed in 2-4 passes on differing directions to get the best possible coverage. Check your local area to determine which turf types are best. Water lightly 3-4 times per week to keep surface moist to encourage germination and until seedlings are well rooted. Continue mowing at 1-1.5 inch height until new seedlings have been cut at least twice then increase mowing height by ½ inch per mowing until back to the normal 3-3.5 inch height. Re-apply starter fertilizer about 4 weeks after germination. Avoid herbicides until seedlings have been mowed at least twice and always follow herbicide labels in reference to new or over-seed recommendations.
If weeds such as dandelions and other winter annuals are the primary cause of thin turf density it would probably be best to control the weeds now and over-seed in the spring.
For significantly thin or damaged turf, it is time for a complete renovation. Start with applying a non-selective herbicide (glyphosate for example). It will most likely require multiple applications a couple of weeks apart to get a good kill. Prepare the soil by packing and removing thatch. A good rotary tillage pass may be needed to remove thatch. Be sure to go 4 inches or deeper if soil is compacted. Apply starter fertilizer and seed, rake lightly to incorporate into the top ¼ inch of soil, and proceed as stated above for the over-seeding process.
As a final note, avoid planting warm season grasses until mid to late spring.