Fall Seeding Cool Season Grasses & Legumes


Whether for lawns or pastures, late summer and early fall offer an excellent opportunity to plant cool season grasses and legumes. In the Midwest, the ideal seeding window for these species is from August 15th to September 15th.

 

Advantages of Fall Seeding Cool Season Species

  • Quicker Germination: Warmer soil temperatures in the fall typically lead to faster germination rates.

  • Reduced Weed Competition: Late-season weeds tend to be less abundant and competitive.

 

Challenges of Fall Seeding

A key challenge with fall seeding is ensuring adequate moisture, as precipitation can be limited during this season. However, a couple of good showers may provide enough moisture for seeds to germinate in warmer soils. In periods of dry weather, irrigation will be necessary for successful growth. Watering daily or every other day during the germination period is usually effective. Be mindful of any irrigation restrictions that may prevent adequate watering in specific areas. If the seeds do not receive enough moisture to germinate promptly, the grass may emerge too late in the season to establish before winter frost, necessitating a spring re-seeding.

 

Overseeding Opportunities

Fall is also an ideal time to overseed thin or damaged areas in cool season turf and pastures. If a pre-emergent herbicide was applied earlier in the year, it's crucial to check the herbicide label for reseeding instructions, as previous applications may hinder germination.

 

Importance of Seedbed Preparation

Proper seedbed preparation enhances the likelihood of success. In an existing lawn or pasture, achieving good seed-to-soil contact is essential for effective germination and growth. This can be accomplished by:

  • Reducing mowing height

  • Removing thatch through aeration or raking

For new seedings, existing grass and weeds should be eliminated using a non-selective herbicide and/or light tilling. Seeds must be planted at the appropriate depth (¼ - ½ inch deep), and the soil should be packed to create a firm seedbed. Developing a weed control plan before planting is crucial, as weed competition is one of the primary reasons for failed plantings.

 

Using Starter Fertilizer

Applying a starter fertilizer can enhance root growth in new seedings or when overseeding. Starter fertilizers typically have higher phosphorus and lower nitrogen and potassium content. The appropriate application amount depends on the current soil fertility, so conducting a soil test for available nutrients is recommended.

Most fertilizers consist of three primary elements: Nitrogen (N), Phosphorus (P), and Potassium (K), listed in that order on the label (N, P, K). For example, if using an 18-24-12 starter fertilizer and you need to apply 1 lb of nitrogen per 1,000 square feet, you would apply 4.167 lbs of fertilizer per 1,000 sq. ft. This calculation is made by dividing the desired amount of phosphorus by the percentage of phosphorus in the fertilizer. In this instance, the equation would be: 1 lb / 0.24 = 4.167 lbs.

Find more information on fertlization strategies click here.