When to Plant Grass Seed in Illinois | Jonathan Green (2024)

FAQs

What month should I plant grass seed in Illinois? ›

Timing is critical to assure success when seeding lawns. Mid August to early September is the ideal time for seeding lawns in northern Illinois. April would be a second choice.

Yes, you can plant grass seed too early in the spring. Planting too early in the spring can cause poor germination, which harms the growing seeds. As such, wait for the air and soil temperature to warm up enough to plant your grass seed.

Aim to seed early in the season, but wait until daytime temperatures are in the 60 to 75 degree Fahrenheit range. This roughly corresponds to the optimal soil temperatures for cool-season grass seed germination. Spring sunshine and rain both contribute to strong grass growth.

When it's October, people often wonder if it is too late to plant new seed. The good news is if you hurry, seed can still be planted in October with the hope that it will survive the upcoming winter. Although September is the best time, often we can still plant grass seed up to October 15 with good results.

For Illinois, the best time to plant lawn seed mixture is mid-August to early September. If you've missed this time frame, you can also plant in April.

Overseeding can help you get back to the thick, lush, green lawn you've always wanted. By spreading grass seed over your existing lawn, you can thicken up the thin areas, and your lawn will start to look terrific again. (This is different from reseeding, which is when you start over and plant a completely new lawn.)

Cool-season grasses go dormant and do not grow during hot weather, when the soil temperature goes above 65 degrees F. Since this is common during the peak summer months, planting cool-season grass seed can result in poor seed germination or even seedling death.

Water new grass seed for 5 to 10 minutes immediately after planting to gently moisten the first several inches of soil.

Before Planting New Grass Seed

A few days before planting your new grass seed, water the entire area about 6-8 inches deep each day. Once you've spread the seed, promptly spend about 5-10 minutes watering the top two inches of soil. The seeded area will need to stay moist so the grass seed doesn't dry out and die.

Best time to attempt spring grass seeding

The best time to seed in the spring is mid-March through early April. Like fall seeding, the soil must first be prepared. The recommended method is verticutting. A verticut slices grooves in the soil that allows for the necessary seed and soil contact for germination.

How do you prepare ground for grass seed? ›

Remove all debris and any wood, stones or large roots. Use a spade and garden rake to scratch the soil 1 to 2 inches at the surface, then dig about 6 inches deep to remove roots and rocks. Add seeding soil to the top of your existing soil and smooth with the rake.

And with the thought of spring on your mind you may also be wondering if you can plant grass seed in winter. Well, planting grass seed in winter is not only possible, but it could also give you that lush, green lawn you've been waiting for. The process of planting grass seed in winter is called 'dormant seeding.

The grass will be thinner, allowing more contact between the soil and your seeds. In late fall the ground is cold enough to keep the seeds from germinating until spring. If they germinate this late in the season the seedlings will be too young to survive the winter conditions.

Through dormant seeding, grass seed can be planted in November when the weather is cold enough to keep it dormant until the weather warms up in the spring. Once spring arrives, the seeds will sprout and grow normally.

Early fall is the best time to plant cool-season grasses, such as Fescue, Rye and Bluegrass. These grasses grow best when the temperature is between 60-80 degrees Fahrenheit, and benefit from the shorter days and cooler nights. There is also less competition from crabgrass and foxtails.

In Illinois, the best time to overseed a lawn is late summer/early fall (late August to mid-September). Soil temperatures at this time of year are still warm, which promotes optimum seed germination, and the cooler air temperatures are better for grass growth.

When to Start Seeds in Illinois. In most cases, the best time to start seeds is approximately six weeks prior to the last frost date. In both Bloomingdale and Carpentersville, that lands somewhere around May 21-31 every year.

Late Spring Fertilization: April or May in Illinois

As your grass begins to come back to life, you'll likely find that lawn mowing is required much more often during this time of year. This is a good sign. Healthy grass is fast-growing grass.

Will grass seed germinate on top of the soil? Yes; in fact, germination will suffer if too much soil is placed on top of the seeds. The experts at Jonathan Green recommend placing a thin layer of mulch or topsoil over them to help keep them moist and warm and promote growth.

Grass seeds are not strong enough to grow through soil. They're meant to be placed on top of loose, prepared soil. Germination can quickly suffer from too much soil on top of them.

What do you put on top of grass seed? ›

The best choice is green mulch, which is made from recycled paper, polymers (think of the moisture-holding capability that polymers give a baby diaper) and starter fertilizer.

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.

Twice daily watering is essential until the new grass is up, then after one more week, reduce to once per day. Adjust this pattern according to season and temperature demands.

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. If it's too cold, the grass seeds will likely rot.

One of the most effective ways to get your grass to grow fast is to fertilize right after you plant. For use on all grass types, reach for Scotts® Turf Builder® Starter® Food for New Grass, which helps grass grow up to 70 percent thicker and 35 percent more quickly (vs. unfed).

After you finish laying down the grass seed and lawn food, cover both with a thin layer of soil to help keep the grass seed from drying out and washing away.

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.

With new grass seed, the aim is to keep the soil moist. Waterlogged soil will suffocate the new seeds. It is best to water the grass seedlings 2 to 3 times a day for about 5 to 10 minutes each time. This way you replace any water that has evaporated without oversaturation.

Do not allow the top ½ inch of the soil to become dry until the grass is 1 inch tall. Once the grass is 1 inch tall, water the grass every other day until grass is established (approximately three weeks). Once the grass is established, revert to watering 1-2 times a week for a total of approximately 1 inch of water.

The main reason grass seed doesn't germinate quickly during the spring months is cool and wet weather. Grass seed that is planted in soil temperatures below 50°F often will not grow. For the soil temperatures to reach 50°F you need 7-10 days of air temperatures to reach over 60°F.

Is March too late to plant grass seed? ›

Is March too early to plant grass seed? In nearly all regions, March is too early to plant grass seed. Temperature is a better barometer; wait until days average about 80 degrees before planting grass seed for summer. March is too late to sow cool-season grasses.

Do not put top soil over grass seed, but you can add a thin layer of organic matter to help the seed to germinate. 'Never put topsoil over newly planted grass seed,' says Yamaguchi. 'This won't provide healthy growing conditions – it will actually prevent the seedlings from sprouting by essentially suffocating them.

In general, it is best to sow grass seed before it rains, as is easier to work dry soil and rake the grass seed into it. Mulching can help keep the seed bed moist throughout the germination and early growth period. Sowing seed after it rains is not only a messy endeavor, but walking on mud can compact the soil.

Grass seedlings are not strong enough to survive a frost. Grass seed typically takes a few weeks to sprout and then several more weeks before it is strong enough to withstand frost.

New grass is more susceptible to frost because the roots are less established. Frost can damage the blades and eventually seep down into the roots. As the grass takes in water, it often absorbs the frozen water on the blades instead of in the soil.

You can't seed once there's been a frost

Myth: Once there's been a frost, there is no chance that seed will germinate. Fact: An early season frost may affect seed that has already germinated, but should not affect seed still in its casing.

Ignoring recommended seeding rates

Don't overdo or cut corners. Too much grass seed causes undue competition for resources such as light, water and nutrients, and grass seedlings struggle as a result. Too little seed leaves lawns thin or bare.

Step 4 – Cover seeds

Lightly drag the grass seed bed so no more than ¼ inch of soil covers the grass seed. Don't forget to protect your seed once it's down. Using a product like GreenView Fairway Formula Seeding Success provides a seeding mulch and start fertilizer in combination.

Applying fertilizer at the same time you seed your lawn is not a recommended idea. Many experts will tell you that doing so you could risk to destroy a large part of your lawn where the soil was heavily fertilized.

Is December too late to seed grass? ›

Grass seed can survive the winter, and planting during the winter season is known as dormant seeding. If you put down grass seed in November or December, the seed will just lay dormant until the soil starts to warm in spring. While this comes with risks, it can also be beneficial and save you time on seeding in spring.

You are describing dormant seeding, where grass seed is planted late in fall so it stays dormant until spring. Then as conditions warm in spring, the seed is already in place and ready to germinate. For northern Illinois, the time to dormant seed would be the last week of November.

Fall is the best time. The autumn season comes with a mix of warm soil and cool air, perfect for planting grass seed and allowing time for new grass roots to develop before winter sets in. It is also a good time to fertilize to build stronger, deeper roots for winter, resulting in a thicker, greener lawn next spring.

Do I apply the fertilizer before seeding or after? Apply the fertilizer before seeding. When is the best time to plant a new lawn? Spring and fall are the best times to plant a new lawn.

Zoysia is an extremely aggressive spreading grass that can literally choke out weeds. Zoysia is pleasant on the eyes and feet. It tends to have a soft, fine texture and is naturally low-growing.

Perennial ryegrass

Perennial ryegrass is so durable that it is a popular grass type for golf courses in northern climates. This is another grass with tough blades and a strong root system. In addition to being able to withstand heavy foot traffic, perennial ryegrass is also fast-growing and drought-resistant.

Planting grass seed in Illinois should be done between August 15 and October 1.

The absolute best time to seed or overseed your Illinois lawn is in the late summer to early fall (from mid-August to mid-September). This will give the young grass two or three months to get established before temperatures get too cold and growth stops.

This is called a Plant Hardiness Zone. Southern Illinois is in Zones 6a-7a. Central Illinois is in Zones 5a-6a. Northern Illinois is in Zones 5a-5b.

You can plant seeds for lettuce, peas, spinach, green onions to be planted and grown throughout the year! Yep, you can start many seeds throughout the spring/summer/fall season! So it's really never too late to start seeds.

Is it better to plant seeds in the fall or spring? ›

In fact, many experts say fall is a better time to plant than spring because while the air might be cooler, the soil is still warm, which encourages root growth.