Now is the time to overseed your lawn, here’s how to do right

Early September is the perfect time to overseed a bluegrass and tall fescue lawn. The combination of warm soils and cooler nights creates just the right conditions for quick germination and establishment.

Soil preparation, seed selection, fertilization and irrigation are important for success.

Prepare the soil by core aeration and/or verticutting to break up soil compaction. Verticutting slices grooves, creating an area for grass seed to fall. This method is preferred for overseeding as it provides an even seed bed.

Start by mowing the grass short (1 to 1.5 inches) and then verticut in one or two directions. Remove any debris from the lawn for good seed-to-soil contact.

High-quality seed is a must. Avoid inexpensive seed that contains species such as creeping red fescue, fine leaf fescue, perennial, annual rye and annual bluegrass. These species may look good quickly after seeding, but they are sure to fail under stressful summer conditions. Check the seed label to ensure you are getting good varieties of bluegrass or tall fescue. No other grass species will tolerate our local conditions. Some of the national brands found on the shelves are filled with inferior species.

Fertilizer is needed by new seedlings to establish quickly. The existing grass benefits from a September fertilizer application.

Unlike the standard grass fertilizer that is high in nitrogen, new seed should be fertilized with a balanced fertilizer such as 13-13-13 or a high phosphorus product such as 10-20-10. Phosphorus is a macronutrient that aids in the root development of young seedlings. Fertilizer should be applied at the rate suggested by a soil test (available through your local extension office) or a starter fertilizer should be used at the rate suggested on the bag.

Experience tells me that most people do not apply enough fertilizer when seeding as they are afraid of burning the new grass. In fact, the opposite happens as there is a lack of nutrition and the seedlings fail to grow.

About four weeks after germination, apply a high nitrogen fertilizer such as 27-3-3 or 30-0-0. This application should be repeated in mid-November to send the grass into winter, strong.

Seeding is the next step and should be applied at half the seeding rate that is used for new lawns. For tall fescue, the normal rate is 6 to 8 pounds per 1000 square feet. The overseeding rate is 3 to 4 pounds per 1000 square feet. This should be broadcast over the prepared area. The new lawn rate for bluegrass is 3 to 4 pounds per 1,000 square feet makings the overseeding rate around 2 pounds. Fescue should germinate in about 10 days while bluegrass may take up to two weeks.

Water in and keep the seedbed constantly moist to ensure rapid germination. Begin with frequent, light irrigation and progress to deeper more infrequent watering as the seedlings become established.

Following these hints will lead to success. Remember, the ideal window to overseed is very short. The greatest success is achieved by having the seed planted by Sept. 20.