Maintaining a healthy lawn doesn't always come easily, especially if your grass has bare patches or looks thin. Overseeding is a popular method that helps to rejuvenate your lawn, making the grass grow thicker and healthier to suppress weed seeds.
Why is Overseeding Important in the Summer?
Summer can be tough on lawns. The perfect combination of heat, drought, and heavy foot traffic during outside play can damage the soil surface, resulting in patches of dead grass, bare spots, and avoidable stress on the grasses that had thrived so nicely in the springtime.
Overseeding makes it possible to repair damage, fill in bare spots, prioritize weed control, and keep your entire lawn looking dense and vibrant, even as air temperatures climb. Plus, you can use it as a time to introduce new, resilient grass seed mixture and improve its overall health year-round. (Perennial ryegrass, here we come!)
Step 1. Choose the Right Time
Early fall and late spring are ideal for overseeding, but you can do it in the summer, too, as long as the conditions for germination are right.
Look for a streak of rainy, cooler days when you also have time in your schedule to commit to regular watering. In arid climates, you may need to wait until late summer for the best chance of seed germination.
Step 2. Select the Right Type of Grass Seed Mix
Not all grass is going to be a good fit for your area. Start by understanding if you need cool-season grass or warm-season grass.
Then, choose a high-quality seed that is well-suited to your region's climate and your lawn's existing grass type. If your lawn gets heavy foot traffic, select a durable grass variety that claims excellent traffic tolerance.
Step 3. Prepare Your Lawn
Before you seed, mow the grass shorter than usual. Then use a dethatcher or power rake to break up the thatch layer—that’s the built-up dead grass and roots sitting on top of the soil surface. This layer can block water and keep new seeds from taking root. Best case scenario, loosen the top inch of soil to improve the seeding rate.
After dethatching, run a core aerator across the lawn. It pulls out small plugs of soil to relieve soil compaction and boost airflow to the grass roots. Removing soil plugs also helps let lots of water flow to the roots while deep watering, and improves direct soil contact. This makes it easier for the plants to establish strong roots.
Step 4. Spread the Grass Seed
Use a broadcast seed spreader to evenly distribute the lawn seed. Hand-held spreaders are useful for small areas, but a broadcast spreader on wheels can make the chore easier for larger lawn maintenance. Apply additional seed to areas that are particularly thin or bare.
Step 5. Fertilize
After seeding, add a starter fertilizer made for new lawns. This gives the seedlings the essential nutrients they need to grow fast and strong. Fertilizer helps a lot in soil that experienced nutrient loss, or shaded areas where grass plant growth can be slower.
For better results, match your fertilizer to the soil type and consider soil testing before applying. Use a fertilizer spreader for even coverage and follow the label instructions so you don’t overdo it.
Step 6. Water Properly
Seedling emergence starts with proper watering. Be prepared for light, frequent watering to keep the soil moist. Avoid overwatering and oversaturatating, because it can wash away the seeds. The placement of the seeds is important for the first week, or until you witness some seedling emergence. Once the grass seedlings begin to sprout, you can reduce the frequency of surface watering, instead focusing on deeper soaking to encourage healthy root growth.
Step 7. Wait to Use the Lawn Mower
Wait until the grass blades reach about 3-4 inches tall before mowing, and even then, set your mower high to avoid stressing your new, green lawn. Keep the healthy grass free of debris and ensure it receives adequate water and nutrients as it establishes.
FAQ
What is the best tool for spreading seed across large lawns?
For big areas, a broadcast spreader or drop spreader makes it easy to cover hundreds or even thousands of square feet. These tools give even coverage and save time compared to spreading by hand. If you're working in smaller spaces or around obstacles, a hand-powered spreader works well.
Can I seed over a lawn with a thick thatch layer?
It’s better to remove the layer of thatch first. Thick thatch stops seed from touching the layer of soil, and that contact is key for grass growth. Use a dethatcher, vertical mower, or power rake to clear the area. Then seed right after, so the seed can reach the soil and germinate.
How do I know the best time for overseeding in hot climates?
In areas with hot summers, wait for a break in the heat. Soil temperatures should be warm enough for quick germination, but not so hot that seedlings dry out. Late summer or early fall often brings better soil temps and a shorter window of cooler nights. Watching the time of seeding helps avoid wasted seed and poor growth.
Should I aerate the lawn before using a slit seeder or vertical mower?
We would. Aerating first helps loosen the soil and improve airflow. If you’re using tools like a slit seeder or vertical mower, aerating can help seeds settle into the grooves they create. This is good for lawns with soil compaction or poor grass seed-to-soil contact. Both methods work well together to improve grass growth.
