September: Time to Reseed Cool Season Lawns
Traditionally September is considered the most important month for care of our cool season lawns, bluegrass and tall fescue. These grasses thrive in the cool of the spring and fall, and stress or even go into dormancy in the dog days of summer. The arrival of September with the milder conditions helps revive the summer stressed turf. It naturally wants to grow and thrive. This is why it is important we give the grass what it needs to fully recover from the stress of summer.
Time to Seed
September is not only good for fertilizing it is also the ideal time to sow new grass seed. September conditions are perfect with warm soils, bright sunshine and cooler nights to establish a new lawn. Successful lawn seeding does require a little thought and a few guidelines to follow. It is not as simple as just throwing out seed and letting nature take its course.
Successful overseeding requires good soil preparation to help improve the contact between the small seeds and the soil. The ideal way to prepare the soil for seeding is to verticut. Think of a verticutter as a machine with a spindle of closely spaced saw blades spinning through the turf. As these blades cut or slice through the soil they open up grooves that allow the seeds to fall and be covered up for good germination.
Before verticutting mow the turf lower and make sure there is good soil moisture so the blades can penetrate the soil. Make one to two passes and then rake up the debris. After that you are ready to seed. Then comes the hard part of making sure the seedbed is moist at all times. Grass seeding requires dedication to watering as it takes even moisture to get a good stand of grass. Most grass seed will germinate within one to two weeks of seeding, and then the amount of water can be reduced.
Seeding is also more successful with an application of a starter type fertilizer. Instead of the high nitrogen application recommended, use a more balanced fertilizer or one with more phosphorus such s 10-20-10. Research has shown that phosphorus placed at the point of germination speeds up establishment. But remember for most lawns the phosphorus is only needed when seeding. Be careful not to starve your lawn with too little nitrogen. A month after the new grass has germinated apply a high nitrogen fertilizer to push the grass for quicker establishment before the arrival of cooler fall and winter temperatures.
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FAQs
Late August to early September is the best time to overseed cool-season grasses. It may still be a little warm outside, but temperatures will quickly begin to moderate as the days get shorter. The easiest way to get new seed into your lawn is to core aerate it first before sowing seed across your lawn.
Can I reseed my lawn in September? ›
September is not only good for fertilizing it is also the ideal time to sow new grass seed. September conditions are perfect with warm soils, bright sunshine and cooler nights to establish a new lawn. Successful lawn seeding does require a little thought and a few guidelines to follow.
Is September too late to plant grass seed? ›
Although September is the best time, often we can still plant grass seed up to October 15 with good results. The problem with late season seeding is that Mother Nature is working against us. Shorter days and cooler temperatures prolong the germination of the seed and its establishment.
When to reseed cool-season grass? ›
The best time to reseed a lawn with cool-season grass seed is in the early fall, between mid-August to early October, and at least 45 days before the first fall frost.
Can you overseed cool-season grasses in the fall? ›
Fall Overseeding
Many homeowners find that overseeding in the fall works very well. Cool-season grasses germinate best when daily temperatures are gradually moving downward as they do in fall, so it can be a great time to overseed without the pressure of summer's dry, hot conditions.
How long does it take for grass seed to germinate in the sept? ›
Whether you're repairing bare spots, overseeding an existing lawn or starting from scratch, you can generally expect grass seedlings to emerge within seven to 21 days when grown under proper conditions. It may take another three to four weeks of growth before grass is long enough to mow.
What is the best grass seed for September? ›
September is the most important month for developing and maintaining a healthy cool season lawn with tall fescue or bluegrass. This time of year, the grass begins its recovery from the stress of a hot, dry summer.
What temperature kills grass seed? ›
If you're wondering how cold is too cold for grass seed germination use our rule of thumb and check the weather reports. If the daytime temperature is below 60°F then soil temperature is below 50°F, making it too cold; if there is frost or still a danger of frost, then it's too cold.
Can I just throw grass seed down on an existing lawn? ›
Overseeding is spreading grass seed over an existing lawn. Done right, it's a straightforward process that gets results. As grasses mature, thinning is normal—especially if you enjoy your lawn and use it often. Overseeding keeps your lawn competitive and steeped in youth and vigor, without starting over from scratch.
What happens if you plant grass seed too late in the fall? ›
In fact, seeds that do germinate late in the season often do not survive the winter because the very young, immature seedlings have a difficult time surviving those harsh conditions.
Can I Just Throw Grass Seed on Bare Spots? Throwing grass seed onto bare spots will result in little-to-no germination and will not help to repair lawn spots. If you want to fix patches on grass, you need to properly prepare the bare spots before laying down the seed.
What is the best cool-season grass to overseed with? ›
Kentucky bluegrass offers the greatest cold hardiness of all the cool-season grasses common to northern lawns, standing up to the extreme winter cold. Fine fescues also have excellent cold tolerance.
What temp does cool-season grass go dormant? ›
Cool-season grasses will start to slow down once temperatures drop below 56ºF consistently and will also enter a "summer dormancy" period if drought stressed. Warm-season grass growth will slow down when temps get below 74ºF and tend to go dormant in the winter when temperatures consistently remain under 60ºF.
What temperature should I overseed my lawn in the fall? ›
Daytime temperatures around 60 to 75 degrees Fahrenheit typically mean the soil temperature is between 50 and 65 degrees and perfect for seed germination. If the soil temperature is much lower than 50 degrees, however, the seeds will lay dormant and not germinate.
How long does it take cool season grass to germinate? ›
Perennial ryegrass will germinate in 5 to 7 days, turf-type tall fescue and fine-leafed fescues will germinate in 7 to 14 days and bluegrass takes 28 days. Once the grass germinates, it will need continual water to develop roots and shoots.
When should you aerate cool season grass? ›
If you have a cool season lawn like fescue or bentgrass, then the best time for lawn aeration is the fall – preferably at least one month before the threat of frost arrives. If your soil is particularly clay-heavy, your grass could benefit from more frequent aeration regardless of turf type.
Is it too late to plant seeds in September? ›
Although September marks the beginning of fall, there are still a few fast growing vegetables that can be planted this month and be harvested before the first frost in most gardening zones. Remember to keep your soil warm by removing all mulch and maybe try using a plastic sheet to trap heat into the soil.
What do you put on your grass in September? ›
September is the best time to fertilize your lawn for fall. The grass is recovering from a long hot summer. It may be coming out of drought-induced dormancy. So, you'll want to give your lawn a fresh shot of nitrogen to push blade growth.
How late can I overseed in the fall? ›
It is too late to overseed your lawn once the growing season has passed. For warm-season grasses, once the summer heat has arrived it is too late. The new grass will not be able to take root. For cool-season grasses, late October on is too late to overseed.
Can you just sprinkle grass seed on lawn? ›
The aeration is able to loosen the soil and also activate the nutrients and make it easier for the seed to absorb when it is putting down its roots. Both of these treatments are performed right before the seed has been planted. If the seed is just thrown on the ground it will cause poor germination.
