The period from late summer into early fall is the best time to establish common cool-season grasses such as orchardgrass, tall fescue, timothy and bluegrass for pasture or hay in Kentucky. These four grasses make up 95 percent of our pasture acreage.
Many years of research have shown this period provides the best chance for successful establishment. Mother Nature has a hand in this because seed produced in late spring remains dormant until late summer, and early fall rainfall provides the moisture necessary for the seed to germinate.
To increase your success rate, remember these four points:
First, address soil fertility needs by applying lime and fertilizer based on a current soil test. Inadequate levels of phosphorous, potassium or limestone will limit the success of late-summer seedings. For pure grass stands, apply nitrogen at the rate of 40 to 60 pounds per acre.
Second, control competition. Late-summer seedings most often fail from competition and lack of water. When you control existing vegetation with herbicides or tillage, the emerging seedlings will have access to whatever water and nutrients are present without having to compete with weeds.
To maximize the success of seedings, use a burn-down herbicide ahead of planting to kill annual weeds. Translocated herbicides can be used where labeled to kill or suppress perennials such as johnsongrass.
Remember to wait two to three weeks after spraying translocated herbicides before you plant in no-till situations. This will allow time for killed weeds to dry out and for residual effects of the herbicide to decay.
Third, select high quality seed of an adapted variety. Planting high quality seed is an essential step toward establishment and longevity of a pasture. These seeds have high percentages of germination, low percentages of weed seed and freedom from noxious weed seed.
Use varieties that have a proven track record of performance in Kentucky. The University of Kentucky conducts extensive research on varietal performance, which can be found on the UK Forages website, https://forages.ca.uky.edu/variety_trials. Here you will find all of the current results for the major forage crops in Kentucky, including cool-season grasses.
Look for varieties that have performed well across several test years and locations. These varieties will have improved yield, quality, persistence, disease resistance or other positive traits.
If you’re uncertain about a variety’s adaptation and performance, you can obtain information on the leading performers in the UK forage variety tests by contacting the Laurel County Cooperative Extension Service.
Fourth, seed at the proper time and depth. Seed legumes and grasses before mid-September. Grasses are less sensitive to later seeding than legumes. The major cool-season grasses will not do well if you simply broadcast them onto existing overgrazed or mowed pastures. Forages should be seeded no deeper than one-fourth to one-half inch.
Late-summer alfalfa seedings are susceptible to sclerotinia stem and crown rot. If sclerotinia has been active in your area or farm, strongly consider waiting until next spring to seed.