The Best Time To Plant Grass Seed: 5 Things To Consider

Before you start planting roses, azaleas, marigolds, and other vibrant flowers, it’s important to first foster a lush, green garden that will beautifully set off their colors. Whether you’re growing grass seeds from scratch or filling in patchy areas to make your lawn thick and green, it’s essential to time the planting just right.

The best time to plant grass seed depends on soil temperatures, expected weather forecast, the type of grass, the timing of your lawn’s last treatment, and the preparation of the soil. However, it’s best to plant warm-season grass in late spring and cool-season grass in early fall. 

Understanding the type of grass seed you have and the conditions it thrives in is the key to seeding success. Let’s look at the best months for planting grass seeds, whether they will grow if you just throw them onto the ground, and what you can do to prepare your lawn for the planting process.

Which Month Is Best to Put Grass Seed Down?

Grass seed

It’s important to understand that there’s no definite answer to this question. The right time to plant grass seed (on Amazon) depends on several factors, such as expected weather forecast, soil temperatures, location, and the grass species itself. 

The local climate is also an important factor that can help minimize the risk of pests and seedling-related diseases. If you live in a warmer climate, you may be able to plant grass seeds earlier than those living in cooler, northern regions. 

Here’s a more in-depth look at the top five factors you should consider before planting grass seed: 

1. Type of Grass

Warm-season grasses, like zoysia grass, centipede grass, and Bermuda grass, thrive in soils that have a temperature of more than 65˚F, while cool-season grasses, like ryegrass and tall fescue grass, germinate well in soil temperatures below 65˚F.

It’s also important to consider the weather. Planting the seeds during extremely harsh winters or summers can cause the grass to die down, as they won’t get enough time or nutrients to properly establish their root system. 

Generally, the best time to plant cool-season grass is in early fall, whereas warm-season grass seeds grow best in late spring. While you can technically plant grass seeds throughout the year, these specific times have the most optimal conditions and will yield the best results.   

Planting grass seed during spring 

For the highest chance of success, you should plant warm-season grasses in spring. This way, they’ll have enough time to establish a strong root system and will be able to withstand the extreme temperatures that might come with winter or summer. 

Starting the planting process in mid-to-late spring will allow the seeds to grow in the most favorable environment and will protect them from any future environmental stresses. 

On the other hand, you should plant cool-season grasses in early spring, or late winter. However, keep in mind that the early spring window poses greater risks, as there might not be enough time for the plant to mature sufficiently before the stress of summer occurs. 

Planting grass seed during fall

It’s best to plant cool-season grasses in early fall, so they have plenty of time to establish their root system before the arrival of spring. Developed deep root systems can help the grass survive the harsh winter months as well.

Plant your grass seeds when the temperatures are between 50oF and 65oF.

Planting grass seed during winter

While you can technically plant warm-season grass seeds in the winter, it’s better to wait until spring. 

On the other hand, you can successfully plant cool-season grasses in late winter. In fact, this might be preferable to waiting for fall.

2. Last Herbicide Application

If you use herbicides or any other chemical treatment to control the weeds in your lawn, it’s best to wait a month after the last treatment before planting new grass seeds. 

If you’ve applied a crabgrass prevention chemical, you’ll have to wait even longer — usually around four months. 

It’s advisable to plan your lawn or garden maintenance in advance so that by the time the recommended waiting period is over, the temperature will be ideal for seed germination. 

If you didn’t save enough time for weeding before planting the seeds, don’t worry. You can continue your normal weed prevention routine after mowing the new lawn at least five or six times. 

3. Weather 

While you can time the planting process according to the average temperature patterns in your area, it’s still better to check the forecast and then determine the best time to plant and grow grass seed. Don’t plant the seeds if there’s an unusual heat wave or cold snap expected in the near future.

Similarly, keep an eye out for rain events. While a good sprinkling can help speed up the germination process, a heavy downpour can cause the seeds to migrate or erode. Remember that you can plant the seeds before a light, steady rain, but not immediately after a heavy one.  

It’s hard to work in muddy ground and too much moisture around newly planted seeds can result in a fungal disease as well, which will eventually kill the seeds.

It’s important to note that seeds can germinate and grow in cloudy weather, as long as the temperatures are within the suggested range for the seed type you choose. 

However, it’s better to avoid planting the seeds on windy days, as it will affect the spreading of the seeds and blow the just-set ones around if they’re not properly tamped down.

4. Preparation of the Soil 

The best time to plant grass seed also depends on when you’ll prepare the soil for seeding. This prep work might include some type of pretreatment, such as herbicides, and that means a month or more of waiting. If you don’t want to wait that long, you can simply get rid of all the weeds with hoes or by hand.

If you’re planning on planting grass seed on bare ground, you’ll have to loosen the top two inches of soil and remove any debris that could restrict airflow. If you’re spreading the seeds over a large area, a light tiller and seed spreader may make the job easier.

If the ground is hard, you might need to aerate it or loosen around six inches of soil. However, if you’re planting the seeds on an existing lawn that only needs a bit of maintenance, you’ll need to take a weekend out of your busy schedule and mow it as short as possible. Then, you’ll just have to loosen the soil in the bald spots.     

Next, you’ll have to check whether the surface is level and add a bit of fresh soil wherever it dips. This will help prevent waterlogged soil after the irrigation process and ensure good drainage.

5. Other Lawn Activities 

Planting grass seed yourself is one of the easiest and cheapest ways to get a lush lawn or improve a large bare lot filled with weeds and blowing dust. However, this doesn’t mean that you can throw a few seeds into the ground and neglect them. You’ll still need to give the seeds and seedlings a bit of TLC early on. 

You should typically avoid walking or running on your new lawn for at least four weeks. Any activities from your dogs or kids can also disturb and damage your carefully planted seeds. 

After germination, the seedlings are incredibly vulnerable as they grow below and above the ground and establish a strong root system. The seedlings can be easily damaged or uprooted, so make sure you don’t walk on them.  

Lastly, don’t mow the lawn until the seedlings reach a height of at least four inches. In fact, the longer you wait, the better. 

Will Grass Seed Grow if You Just Throw It on the Ground?

Planting new grass seed to bare spot on yard

While grass seed will indeed grow if you just throw it on the ground, planting the seed this way will have a few negative effects. Over time, the grass will weaken and eventually stop growing because it’s not rooted into the soil properly. 

To help ensure a lush, green lawn, here are a few tips on how you can plant grass seed properly: 

  • Test the nutrient levels of your soil with a soil testing kit (on Amazon). If the test shows any serious nutrient deficiencies, fix them before planting the seeds. This could include adding nutrients, fertilizers, or a liming product. 
  • Prepare the planting site by removing any debris and stones, and raking over it to ensure it’s even, level, and as aerated as possible.
  • Immediately after planting, lightly rake, top dress, or roll over the area with a mat or any similar device. This will help encourage seed-to-soil contact.
  • Lay hay or straw over the planting area to protect the seeds from birds and prevent them from washing out in the rain. 
  • Water the seeds lightly every day until they germinate, then water them more deeply but less frequently for the next couple of weeks. 

Should You Soak Grass Seeds Before Planting?  

Some grass types like bluegrass and bentgrass are notorious for their slow germination process. However, soaking the seeds before planting can help speed up the process, leading to a quicker and greener turf. 

Here’s what you need to do:

  1. Place the seeds inside a porous material, like a burlap sack or cheesecloth. Tie it at the top to make a bag. 
  2. Place the sack inside a covered container, such as a fish tank.
  3. Soak the seeds in water for around three to five days. Make sure you soak bluegrass for five days.  
  4. Check whether all the seeds are wet and then place the container in a dark place at a temperature of around 65˚F to 72˚F. 
  5. Change the water after every 12 hours. 
  6. After three to five days, remove the bag from the container and drain the excess water from both the seeds and the bag.
  7. Prepare the planting site. 
  8. Place the seeds in the soil and lightly rake over it. If you have sandy soil, water them as well. 
  9. Irrigate lightly but frequently and keep the seeds moist. 
  10. Follow the specific planting instructions for the seed type that you’re using. 

How Do You Prepare Your Lawn for Seeding?

Once you’ve chosen the planting site, you’ll have to prepare the soil for seeding. First, get rid of any existing grass with a sharp shovel. If you have to prepare a larger area, using a sod cutter might make the job easier. 

Then, walk around the lawn and inspect it closely. Fill in any low spots, remove all the debris and large rocks, and if there’s any compacted soil, loosen it up with a tiller. It’s important to break down the soil into marble- or pea-sized particles, so you can provide your grass seed with the most optimal conditions to grow in.

Here are a few more tips that can help prepare your lawn for seeding: 

Even Out and Level the Surface 

There shouldn’t be any valleys or peaks in your new lawn, so use a garden rake (on Amazon) to make the ground as even and level as possible. While raking, remove any debris or rocks you come across. 

You can fill any dips in your new lawn with topsoil. However, make sure you don’t go for a low-quality one as it might have weeds that are extremely difficult to control. 

Instead, opt for a mixture of rich, composted materials, as it will enhance soil quality and create the ideal seed-growing environment.

Cover Up

Once you finish planting the seeds, cover them with a thin layer of soil to prevent them from drying out or washing away. Add less than ¼-inch of topsoil over the planting site and gently rake over it. 

If you’ve planted the seeds on a hill, a thin layer of mulch and straw can help protect them from the rain. Just make sure that the seeds are visible beneath the straw. You can mulch the rest of your lawn as well to reduce water usage. 

Lawn Maintenance 

  • Mow your lawn after the grass grows at least three inches tall. However, make sure you only cut the top ⅓ of the blades when you mow. 
  • It’s better to use your mower on a higher setting, as this will help keep your lawn thick and lush. If you cut the grass too short, it will start to weaken and allow weeds to set in. 
  • While the seedlings are still new and developing, try to avoid walking on the lawn as much as possible. 
  • Start a routine lawn fertilizer program after six to eight weeks to keep your grass nice and thick.

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