Ahh...Springtime! The sun shining outside and the temperature increasing signifies the end of a long, cold winter. The chirping birds greet you as you open your front door and examine your finally-thawed lawn. Often times, people stare in horror at the patches of brown, dead grass that is covering their lawn. If these bare spots are not over-seeded they will more than likely be overtaken by weeds or insects. Spring seeding often cures the Winter Time Blues.
Although the best time to seed a lawn is in the fall, it can be done in the spring if done properly. It is important to have good seed to soil contact through good soil preparation. It is also important to control weeds in the lawn because spring germinating weeds will out-compete the desirable turf-grass. The downside to spring seeding is that you can't put down a pre-emergent to hold back crabgrass. Below explains how to properly seed an existing lawn and how to seed a new lawn.
Over-seeding an Existing Lawn
- Mow the area to an 1" or 1.5". This will reduce competition from established grass.
- Apply a starter fertilizer (fertilizer high in phosphorus) over the entire lawn.
- Core aerate the area where the seeding will be done. This will help improve the germination rate and also increase the seed to soil contact. Remember there is no such thing as over-aerating a lawn before seeding.
- Apply the seed to the lawn. If the area that is being seeded is large it may be best to use a machine spreader. If the area is small, the seed may be applied by hand. Be sure to make 2-4 passes over the lawn in different directions to ensure an even spread. If you aerate your lawn before seeding, the seed will fall right into those grooves and ensure great seed to soil contact.
- Water the newly seeded area. It is important to keep the seed moist (not soggy) until all seeds have germinated. If the seed/sprout dries out there is a chance it will die out. Normally watering twice a day is enough for new seed to stay moist. Remember, established lawns do not require as much as newly seeded lawns.
- Six - Eight weeks after germination, apply a starter fertilizer that contains nitrogen, phosphorus, and potassium.
Problems to avoid when watering newly planted seed
- Over-watering results in puddles. This can cause the seed to float around or move and then the grass is not evenly distributed.
- Runoff on sloping ground. If the area that was seeded is on a slope it may be necessary to reduce the amount of water and do it more frequently.
- Over-watering that allows the soil to get soggy. It take some soils a long time to dry out. Clay soil is often the worst. Be sure to stay off of the area if this happens.
- Pay attention to areas that are more shaded. These areas need less water, while sunny areas need more.
- Be careful not to under-water new grass seed. One mistake that could lead to starting all over again.
- If you see moss or algae growths showing up, especially in shaded areas, there is too much moisture present.
Seeding a new lawn
- On un-compacted soils, you can core aerate your lawn to ensure seed to soil contact.
- On compacted soils, you will want to till the soil 4-6 inches, rake smooth, allow it to settle for a week or so, rake it one more time and then apply seed.
- On lawns with an excessive amount of thatch, you will want to loosen and remove as much thatch as possible. If the thatch is over 1" thick, either use a sod cutter or till the soil to turn the thatch under.
- Before you apply the seed, use a starter fertilizer over the entire lawn.
- After seeding, make sure there is good seed to soil contact. A LIGHT roller may be used to ensure seed to soil contact. Or if you used a rake, make sure the grooves are big enough to trap the seed.
- Water the newly seeded are to encourage germination. Keep the seed moist, not soggy, at all times.
- As soon as the grass reaches 2.5-3" you are able to mow.
- Six - Eight weeks after germination, apply a fertilizer containing Nitrogen, Phosphorus and Potassium.