How Often and When to Water New Grass Seed
October 31, 2022

How Often and When to Water New Grass Seed

By Adam Chronister

Growing a new lawn in front of their house is a dream for many people. Installing real grass and maintaining it is no joke. While many homeowners tend to resort to artificial grass, the ambiance that natural grass can create is unmatched. You can’t find real grass's freshness, smell, and soft touch on artificial turf. Kudos to you if you have decided to take on this tough job of creating a new lawn. I am sure there are at least a tonne of questions that you would like to find answers to if you have been working on planting grass on your bare lawn areas.

So, we will resolve one of your biggest concerns today - about properly watering the grass! By the end of this post, you will have gathered enough knowledge to water your new grass and have a healthy lawn properly.

Watering new grass seeds seems like an easy job. Get a simple lawn sprinkler, and you are done. However, the timing and quantity of water are really important. There is a very thin line between overwatering and underwatering. We will help you stay on the fine line and master the art of watering new grass seeds. Keep reading to learn how much and how often to water grass seed.

What happens when you overwater or under-water the new grass?

Water the grass

Many people believe that the more you water the grass, the better it will grow. This is a myth that needs to burst. Some seeds need more water, while some don’t. Moreover, there are different stages a seed goes through before it germinates, and the quantity of water needs to be adjusted accordingly. We will learn all these things in detail in a while, but for now, let’s discuss what will happen if you cross that thin line. 

Over-watering refers to watering the grass plants more than they need. There are some major problems associated with over-watering. One is that it restricts the growth of strong roots. Roots become stronger as they go deep into the ground for water. If they start getting all the water close to the surface, the roots will become weak, and your grass can be plucked out easily by heavy wind. Another problem is that it invites insects and promotes algae-type growth. 

We have under-watering, meaning you can’t provide enough water for the grass to grow. Underwatering impedes the growth of grass seeds. Since no water seeps into the ground, the roots come to the surface to get water. They become dry and weak. 

The right amount of water is the secret to a healthy lawn. It isn't easy to estimate the exact amount in the first go. Since the amount of water a plant needs depends on the temperature, the nature of the soil, the type of plant, and the plant's growth, one cannot give you an exact number. It’s a lot of trial and error. 

Let’s look at some signs to help you determine the right amount of water your lawn needs.  

Signs that you have over-watered 


A lot of water is an invitation to all sorts of insects and fungi. If you observe any algae-type growths on your lawn, you can conclude that you have been over-watering your lawn. 


Weeds are prevalent in any lawn, but over-watering can increase the amount of weeds in your lawn. Weeds are harmful because they use up all the water and sunlight your plant needs, stopping the growth of your lawn. 


Your lawn's excessive dampness and loose soil may make it harder for dead plant matter to decompose. Thus, resulting in thatch. Thatch is a dense layer of partially degraded grass roots and stems. Thatch can develop and block nutrients from getting to your lawn's grass roots, resulting in the grass with shallow roots. Thatch is also an open invitation to insects that harm your grass. 

Signs that you have under-watered 

Shallow roots 

Shallow roots are caused when the grassroots reach the surface to get water.  

Footprints stay longer 

If footprints stay longer than 30 minutes, the grass is not watered correctly and might do well with light watering.

Dry soil

Moist soil is necessary for grass to grow properly. If you are not watering the soil regularly, it will go dry and slow down the germination process for newly sown seeds. 

How much, How often, and When

Water Grass Seed

There are many steps in lawn preparation. First, you must prepare the soil, sow the seeds, and then wait for the seeds to germinate. There are a few stages before you can see a lush green lawn. The requirement for water in each step is different. Learn when, how much, and how often to water grass seed. 

Here’s how often to water grass seed. 

Before plantation 

You cannot directly sow the grass seeds or seedlings into the soil. The soil must be prepared to support the grass seed's growth properly. You can start by sending a soil sample for testing. With this, you can achieve the perfect pH level. You also need to remove weeds, thatches, and unwanted plants. Aeration is also a process you should work on. Also, ensure you have a proper irrigation system for your new grass plants.

Soak the ground to a depth of at least six to eight inches a few days before sowing the new grass seeds. You can use a stick, a screwdriver, or the back of a long paintbrush to check the water level. Here's how.  

After watering the yard, simply stick the stick into the ground. The stick should penetrate the earth without any resistance. Remove the stick whenever you see that you need to apply a lot of pressure to penetrate it further. Then, measure how long it was able to penetrate the earth. You are on the right track if it is between 6 and 8 inches. If the measurement is less, adjust the amount of water.

Also, ensure that this measurement is constant in all lawn parts. Use the stick on a few different spots on your existing lawn to verify that the water level is the same throughout. 

Right after plantation 

Water your lawn steadily for 10 to 15 minutes with a gentle but continuous flow just after you've planted the seeds. The water should only penetrate three to four inches below the surface at this time. The water flow should be gentle; otherwise, the seeds might wash away as they don't have roots to hold them in the soil yet. Wait for a whole day to water again (unless the temperature is too high).

Before and after germination 

During these initial stages, germination is most effective, so it's crucial to prevent the drying out of your seeds. According to how much rain falls, water the area once or twice daily to a depth of one to two inches.

It is okay to reduce watering to once daily for 10-15 minutes after you start seeing some small green grass coming up from the ground.

After growth 

After your grass has grown to a height at which it is safe to mow, you can shift to one or one and a half inches of water below the ground level per week. If the temperature is too high or you start seeing signs of under-watering, you can increase the volume of water. If it rains, you don’t have to worry about watering, but please observe the lawn for any over-watering symptoms and take some countermeasures immediately. 

Cool Season Grass VS Warm Season Grass 

There is one more thing we need to talk about, and that is the two major types of grass. 

  • Cool-season grasses are grasses that have adapted to growing in colder conditions. They grow the best when the temperature is between 60-75 F. 
  • Warm-season grasses can survive under high heat. They grow perfectly when the temperature is between 75-90 F. 

These types of grass need different quantities of water. Most well-established cool-season grasses require roughly 1 inch of water each week through watering or rainfall. Approximately 20% more water is needed for cool-season lawns than warm-season lawns. 

So, if your lawn has cool-season grass, you might need more water. Keep looking for the signs of under-watering or over-watering that we discussed earlier. Observation is the best way to find the ideal amount of water you should use. 

What is the ideal time of the day to water the new grass seeds?

The ideal times of day to water grass seeds are generally thought to be in the morning and evening. However, mornings are ideal. Watering before the sun peaks in the sky allows the extra water to drain gradually during the day, which prevents mold, insects, and over-watering of your soil.

How long does it take for the new grass seed to grow? 

All the seeds you sow won’t grow at the same time. Some seeds can germinate within five days, while others take a month. Just be patient with the new seeds and let them grow. 

A few grass seed watering tips for a healthy lawn

Grass Seed Watering Tips

  • Use mulch before watering the new grass seed. Mulch helps prevent soil erosion and retains soil moisture. It is not mandatory, but if you can, please do it. 
  • Keep checking the shady areas of your lawn. That is where algae and moss grow since the water doesn’t evaporate faster. 
  • Ensure your sprinkler sprinkles water uniformly and there are no puddles of water in your lawn. 
  • Oscillating sprinklers are best for new grass as the water gets more time to seep into the ground. 

Bottom line 

The key to a lush green lawn is proper watering. Watering the lawn in the right amount and at the right time is crucial. Building a lawn is fairly difficult, but not when you have enough knowledge about watering it. Watering can either make it or break it. Make sure you follow all the suggestions given in this article. Enjoy time with your family and friends on your very own lawn that you created with a lot of effort.