How and When to Seed Lawn Grass?
There are many reasons why you may want to reseed your turf. You may have a lawn that easily succumbs to disease, insects or drought. Apart from this, your lawn may have been overrun by difficult to control weeds. Over seeding the existing lawn with new improved varieties of the same species, or a new different species all together, can turn a problem lawn into one that is attractive and easier to care for.
Selecting the right type of grass seed for your lawn
Many people are confused about grass seed, as there are so many varieties out there on the shelf to choose from. First, it is important to understand the conditions of your lawn – which variety of grass you are currently using, whether it is sunny or shady, whether it has high traffic or not. For instance, if you currently have bluegrass, you would want to look for a bluegrass seed mix or if you have mostly perennial rye, you would want to look for that type of mix.
Most healthy lawns have a mixture of perennial rye, bluegrass and fescues. The blue grass gives you that wonderful sun loving thick green look. The perennial rye grass is good for high traffic and the fescue is good for high traffic as well as shady areas. Therefore, when you have this combination, you have a very healthy mix of grass seed that will give you a healthier lawn. Mixing will also ensure that if your grass does succumb to disease, it will not wipe out your whole lawn at one go.
Many different varieties of grass grow in different places and these fall into two major categories – Warm Season and Cool Season. Cool season grass species remain green all year round. They grow best in Northeast, much of the Midwest and Pacific Northwest regions. The most well known types of cool weather grasses are tall fescue, ryegrass, bluegrass and creeping red fescues. They can be grown individually or in combination. Warm season grasses are grass types that go dormant in wintry weather. They grow best in the states of South and Southwest. The most common varieties of warm weather grasses are Bermuda, St. Augustine, Centipede, Zoysia and Bahia. Warm weather grass types are not usually mixed together.
Knowing what type of grass you have in your lawn will make it easy for you to choose the correct seed types that will keep your lawn lush green and weed free. You also need to know how big your lawn is. This is to make sure that you have the right amount of seeds for good coverage. You should check the product bag label for recommended coverage rates. Choosing high quality seeds is very important. No matter how well you prepare the soil, if the seed is low grade, the results will be poor. High quality seed will have a seed certification tag on the product indication, the level of seed germination, the percentage of weed seed and inert content. The weed seed should not exceed five tenths of a percent. It may cost a little bit more, but the results are obvious and your overall costs for the project will be less.
Know the best time to plant grass seed
For cool season grasses, when you want to over seed or plan new seeding for your lawn, you should do it when temperatures are cool and there is adequate moisture to germinate your grass. There are two times in a year when these conditions are met – early spring or late summer to early fall. If you plant seeds during late summer or early fall, the seeds will have sufficient time to establish, before the hot dry summer approaches and stresses out your seed. However, you may want to aerate the lawn just to get better germination. The basic thing to look before seeding your lawn is the day and night temperatures. The outside temperature at night should not be colder than 40 degrees and during the day, the temperature should not get hotter than 75 degrees. The warm season grasses can be seeded in early spring and into the summer. The ideal daytime temperature should be between 75 to 90 degrees for optimal germination of warm weather grass. View Plant Hardiness Zone Map.
Preparing the soil for planting grass seed
Creating a healthy lawn starts with soil. Before planting seeds in the soil, you need to prepare the ground so the seedlings can develop as well as possible and grow faster. It is important that the ground is soft, rich and permeable. The initial step involves removing any existing vegetation or weeds that might be growing on your property. If the grass is tall and there are many weeds, use a heavy-duty lawn mower to mow your lawn first. To further remove all grass patches and weed roots easily, you may use a non-selective herbicide while the plants are actively growing at temperatures in the 60’s to 80’s.
Use products containing Glyphosate only, as some brands in addition to Glyphosate contain long lasting soil sterilants, which will prevent your new grass from growing and can harm trees growing in your yard. Just follow the user instructions carefully on the label. Two applications of Glyphosate should be made roughly seven to ten days apart to ensure complete kill. Difficult to control grasses and weeds may require a third application. If a thatch layer, greater than one inch deep is formed above the soil surface, it is best to remove the thatch and dead sod prior to aeration and over seeding. Using a sod cutter can make this process easier. If the thatch layer is less than one inch thick, you may leave the dead turf on the lawn. It will break down adding organic matter to the soil over time.
If you have an irrigation system, mark all sprinkler heads with flags and take care not to damage them while tilling or while removing any existing grass or debris. Make sure to remove any rocks, twigs or branches from the area before tilling. Aeration or core cultivation of the dead lawn is the next step. The aeration holes provide perfect condition for grass seed germination. The key to effective aeration is to ensure that the ground is moist but not soggy on the day of aeration. Aerate in different directions. The more holes you have and the more uniformly spaced they are, the more quickly you will have a usable lawn. If you have a small lawn, you may aerate the soil manually using a rake or aerating shoes.
You may also rent/buy a tiller, which will loosen the top soil layer as well as aerate the ground. Tilling services cost more than aeration, as it requires more work but is better in the long term. After tilling, a layer of about 40 cm of soil will be soft, rich and suitable to receive the seeds. Next, spread organic fertilizer on to the soil, which in addition to enriching the soil improves the texture. If the soil is very compact and clayey, add sand and peat mixed together.
Planting grass seeds after soil preparation
After having worked the soil with a rake or a tiller, level out the surface, avoiding production of humps or hollows. This prevents water accumulation and stagnation. Then proceed to sowing by choosing good quality seeds in a mixture that is suitable for the place. To spread the seeds better, you can mix them with sand, so that you can see where the seeds fall on the ground. Distribution rates will depend on the grass species being seeded. Usually, for 30 to 40 square meters of land, you will need about a kilo and a half of seed. You may use a hopper spreader to distribute seeds evenly. Drop spreaders control seed distribution more effectively than broadcast spreaders.
Once you have scattered the seed, pass over the surface with a roller, which will put the seeds perfectly in contact with the ground. You may also gently tap the surface with a poly rake to ensure the seeds are firmly planted in the soil and are protected from birds. Then water the soil to moisten it to a depth of about 15 to 20 cm. Remember, the water must be supplied to the lawn in such a way that you avoid creating runoff on the surface of the ground, as this tends to displace the seeds from their original position. Therefore, use a very fine spray of water. Water the lawn daily for 3 or 4 weeks consistently to allow those seeds to establish and take hold of the soil below.
Depending on the time of the year and the soil temperature, seed germination may take anywhere from a few days to a couple of weeks. For instance, Kentucky bluegrass will germinate in 7 to 10 days in the summer or early fall but may take two to 3 weeks to germinate in cold spring because of colder soils. When the young grass grows to a height of 2 to 3 inches tall, begin to mow the lawn, as you normally would. Do not let the new grass get too long before mowing, as young seedlings might get damaged.