As the summer is quickly coming to a close (though not quick enough) we will all be thinking about getting ready to overseed our turf. Just as the Bermudagrass is just starting to look its bests around the middle of August, we begin dropping our mow heights to begin preparing to throw Ryegrass seed around the beginning of October. This can be a very successful process, or it can be a disastrous one that you will pay for the following 3-4 months. Blame it on the weather ‘these 100+ degree days zapped all my seed!’ or blame it on the seed ‘my germination rate was very low this year, it must be bad seed!’ Whatever you decide to blame it on, here are a few keys that will be helpful in overseeding success.
- Check all nozzles before overseeding, just after dropping to your final mow height. Mowing to ½” can sometimes displace your spray head or cause problems. If these problems are fixed after the seed is down, you may run into problems like seed washing away if sprinkler head repairs are required and flooding occurs.
- DO NOT scalp! True scalping of turf is not recommended because of a few reasons:
- Can cause excessive damage to Bermudagrass, delaying its appearance next season
- Scalping stresses out the turf, increasing the risk of disease and insect infestations
- Seed can more easily dry out because there is less moisture- holding thatch and organic matter
- Make sure mower blades are sharpened or replaced just prior to dropping mow height
- When dropping mow heights, ONLY REDUCE HEIGHT BY 30% PER WEEK
- You may have to begin dropping your height at the end of August to safely drop it to ¼- ¾” depending on Bermudagrass variety
- Consider leaving some clippings behind as they will act as a mulch protecting seed from drying out (leaving clippings behind will not cause thatch issues)
- Rechecking irrigation daily at different times of day for 1 week after seed has been thrown
- Irrigation is often the reason for spotty germination or seedling failure, check and recheck often!
- Calibrate your spreader and confirm your square footage
- Too little seed will be sparse and won’t look good until spring, too much seed can choke out each killing seed
- Begin fertilizing within 2-3 weeks of overseeding, continuing to apply fertilizer every 4-6 weeks through the winter and spring
- For recommendations on the ideal fertilizer formulations and fertility programs, please give me a call
It is best to wait to overseed until nighttime temperatures are in the mid 50’s or low 60’s. Depending on weather and other environmental factors, you will likely have your first mow about three weeks after seeding or when seedlings are about 3” tall. Good luck out there, and remember cool weather is coming; it may just be November before we see it!