How and When to Plant Grass Seed
Before You Start a Lawn Seeding Project
There are a few things to think about to help your grass get off to a good start:
- A healthy lawn needs good soil. Most turfgrasses prefer neutral soils. To be sure that your efforts aren’t in vain, always perform a soil test first and make the recommended amendments.
- Don’t apply a weed preventer (liquid or granular) or use weed and feed fertilizer when planning to sow grass. You can control weeds only after you have mowed new grass seedlings at least four times. Any weed controls applied when you sow seed will prevent germination or kill immature seedlings.
Before seeding, first identify the type of turf currently growing in your lawn. If starting from scratch, select a turf type suited to grow in your region, and remember the specific requirements of your yard.
Grass seed labels help you determine characteristics of the grass, such as amount of daylight, hardiness and moisture requirements. Turfgrasses are either cool-season grasses or warm-season grasses. In general, where you live determines your lawn type.
On the map, cool-season grasses are suited for areas shaded in light blue. Warm-season grasses grow well in the areas shaded in pink. In the transition zone (darker blue on the map), mixtures or blends of warm- and cool-season grasses are sometimes required. Normally the transition zone has more success with the cool-season grasses over the warm-season varieties. Additional factors, such as altitude, the amount of sun or shade, the amount of foot traffic and the availability of water may affect the success of a turfgrass variety.
- Should be seeded from March through September, depending on your specific location and weather patterns
- Need hot summers and mild winters
- Grow during summer
- Go dormant in fall and winter
- Thrive in temperatures above 80°
- Generally need less water, making them drought-tolerant
- Tend to have wide, coarse blades
- Should be mown close to the ground
- Are often overseeded with annual grasses for year-round color.
- Are generally creeping varieties
The major warm season varieties are Bahia, Bermuda, carpetgrass, centipede, St. Augustine and Zoysia.
- Are seeded mid-August through mid-October, depending on specific location and weather patterns
- Thrive in regions where winter temperatures reach below freezing
- Grow during spring and fall
- Go dormant in summer
- Thrive in temperatures from 60°
- Have longer, finer blades
- Are maintained at a higher mowing level
- Are generally bunch varieties
The major cool season varieties are bentgrass, bluegrass, fine fescue, tall fescue and ryegrass.
What a Grass Plant Looks Like
Creeping grasses, like bluegrass, Bermuda and most warm-season grasses spread by above- or below-ground runners. Creeping varieties are more prone to thatch.
Bunch grasses, such as fescue and ryegrass, spread from the crown of the plant. Mowing high protects the crown and ensures the survival of the grass.
Composition of a Grass Plant
- Blade – What most of us call a blade of grass is actually a complex combination of the grass stem, sheath and nodes. If it grows tall enough, a seed head develops.
- Crown – the base of the grass where all new growth originates.
- Rhizome – a horizontal below-ground stem or runner. Creeping grasses spread by rhizomes or stolons.
- Roots – the below-ground system that sustains the grass. Water and nutrients are absorbed by the roots.
- Seed head – the flower of the grass plant.
- Stolon – a horizontal above-ground stem or runner. Creeping grasses spread by stolons or rhizomes.
- Tiller – made up of leaf blades and sheaths, the stem and sometimes a seedhead. They grow from the crown of the plant. Bunch grasses spread by tillering.
Understanding Grass Seed Labels
State laws require labeling on grass seed. There’s a lot of information listed. For the consumer, look at a few items:
- The amount of the named variety by percent of weight
- Other crop seeds in the package by percent of weight
- Any inert ingredients in the package by percent of weight
- Percent of weed seed in the mixture (if any)
- Germination rate of the seed. The higher the number, the better
In addition to reading the label, there should be a coverage chart to help you determine how much seed you’ll need for your application. Also look to for information on the drop rate for your model of spreader.
Seed Blends and Mixes
In addition to planting pure seed, blends and mixes are also available. A blend is a combination of two or more cultivars of the same species — for example two types of fescue. A mix is a combination of different species of grasses. Both blends and mixes are formulated for specific regions and needs, using the most desirable traits of each grass type to improve the lawn.
You’ll apply the seed with a broadcast spreader or hand spreader. The coverage rates vary based on the type of seed you choose.
Read the label carefully on all lawn-care products. Make sure that the pre- or post-emergent herbicides and fertilizers you purchase are approved for use on your type of grass. Consider how you use your lawn. If you have a lot of foot traffic or children playing, look for a lawn seed with a high traffic tolerance listed. Play areas, especially under swings and other play equipment, also need a tougher turf.
Seeding a New or Existing Lawn
Seeding a New Lawn
Using seed is the most common method of planting turfgrass. Whether you have an established lawn or you are starting a new one, the basic principles are the same.
1. Dig or till to a 3-inch depth.
2. Rake to remove clumps and clods.
3. Smooth and level the surface. Remember, you are establishing a finished grade so include any contours needed for drainage.
4. Add compost, topsoil and starter fertilizer and work them into the soil.
5. Roll with a weighted lawn roller.
6. Spread the seed. To ensure even coverage, sow half of the seed in one direction and the other half at a right angle.
7. Rake and roll again.
8. Mulch with a weed-free straw, such as wheat straw. As an alternative, you can use a seed starter mat or seed blanket to help keep the seed and loose soil from washing or blowing away.
9. Water frequently to keep the seeds moist (don’t saturate). Cut watering back to once a day when the grass reaches about 1 inch in height.
10. Mow when the grass reaches 2 1/2 inches – 3 inches.
11. After it’s been mowed three times, use a regular watering schedule of 1 inch per week.
12. Apply a pre-emergent crabgrass control to stop germination of unwanted grass.
Overseeding an Existing Lawn
To fill out an otherwise healthy lawn or to add extra green for the winter months, you can overseed:
1. Mow lower than usual.
2. Dethatch if needed or rake to thin the existing turf.
3. Aerate to reduce soil compaction.
4. Amend with compost.
5. Add starter fertilizer.
6. Apply seed.
7. Rake in loosely.
8. Top-dress with mulch, compost or peat moss.
Fixing Problem Lawns
Fixing Bare Spots
If your only problem is a bad spot or two, spot seeding can do the job:
1. Make sure the damage is not from a pest.
2. Remove dead grass and loosen the soil.
3. Spread grass seed and rake it in.
4. Mulch with a thin layer of weed-free straw, such as wheat straw. As an alternative, you can use a seed starter mat or seed blanket to help keep the seed and loose soil from washing or blowing away.
Repairing or Renovating a Lawn
If 50% of the lawn is still good (not bare of grass or full of weeds), repair. If not, start a new lawn. Follow these steps in the area you’re repairing or restarting:
1. Mow lower than usual.
2. Apply nonselective herbicide.
3. Wait 10 to 14 days (or as directed by the product label).
4. Seed as a new lawn.
Proper Watering of New and Established Lawns
The amount and the timing of watering are very important. You must keep newly seeded lawns moist by light, frequent watering in order for the seeds to germinate. Keep the soil moist (but not saturated) until the new seedlings are about 1 inch tall. Be careful: too much water can rot the seeds or wash them way.
After your grass is established, remember these tips to keep your lawn adequately watered:
• Water in the early morning if possible. The lack of wind minimizes evaporation and the chance for fungal diseases. However, if you see that the lawn or garden is becoming stressed or endangered from lack of water, go ahead and water without delay. Avoid watering with sprinklers on windy days.
• Water lawns irregularly, rather than on a strict weekly schedule. This replicates natural weather patterns and helps make lawns more drought-tolerant.
• Water deeply and allow soil to dry slightly between waterings. This will help promote root growth. A strong root system creates hardier turfgrass. Light, shallow sprinklings evaporate before water is able to saturate the soil where it’s needed.
• Remove lawn thatch and aerate when needed to increase the soil’s water absorption.
• If you have an underground sprinkler system, keep it adjusted and well-maintained.
• Locate and remedy any spots that are prone to runoff and erosion.