How Long After Planting Grass Seed Can I Mow?
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How Long After Planting Grass Seed Can I Mow?

If you have a lawn, then chances are you are particular about its health. When I became a first-time homeowner, it came with a beautiful back lawn, and I quickly became a lawn fanatic – setting the sprinkler system right, fertilizing, mowing religiously, freaking out when a brown spot appeared…

If you own lawn you will most likely end up having to lay down some seed to cover barren ground, or overseed at some point, especially if you have children or pets. But when exactly will that seed grow into a lawn? And more importantly, how long to wait after planting can you mow?

How Long Does it Take Seeded Grass to Grow?

Depending on the type of seed you have spread, it may take anywhere from 5 to 30 days until you begin to see anything happening, and many factors need to be considered during this process as well, including the age of the grass seed. So don’t feel you are a failure if your space is still a barren brown after a few weeks, especially if you’ve properly prepared the soil and fed your nascent lawn with fertilizer.  According to The Garden Counselor, moisture, warmth, oxygen, and light are important details to consider as well when thinking about seed germination success.

How do I Water my Lawn For the Best Grass?

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Moisture is the number one factor to consider when wondering how soon your seeds will burst to life, and how long you will need to wait until you can add a lush carpet of new grass into your lawn care schedule. Watering new grass seed correctly is crucial to the germination, growth of the seedlings, and root creation during the entire life of your lawn. Proper moisture maintenance from the beginning will develop your new growth into the lawn you always wanted.

Seeds and seedlings need to be kept moist (not drowned) at all times to keep from drying out. According to Scott’s Lawn Library, the top 1 inch of soil should be kept moist at all times (a twice-daily watering should do it), and the area watered daily after sprouting until you have mowed at least once. Seed hulls need water to soften in order to germinate, and new growth doesn’t have the roots to survive any type of dry spell. A general rule to remember is: if it dries out, it dies out.

Once your seedlings have the proper roots to survive, watering properly will help to ensure a long, healthy lawn life. Healthy, deep, water seeking roots means strong plants for optimal growth- and root depth is directly related to grass height

What is Optimum Grass Height for a Healthy Lawn?

Don’t get too excited and begin to prep your lawn mower once you begin to see new growth! Water isn’t the only thing to consider when growing your lawn from seed. As mentioned, a lawn’s height is directly related to its root system, so you need to keep your grass at the right height to keep those roots deep and healthy.


A lawn kept right around 3 inches following the ⅓ rule is the perfect height to ensure healthy new growth before cutting again, as well as the added benefit of crowding out unwanted weeds. Since roots anchor your seedlings into place, if you mow too early you can rip your new growth right out of the ground, negating all the weeks of watering and anxious waiting for the green to appear.

For new grass you want to be sure the grass has reached at least 3 ½ inches in height, if not more, before cutting for the first time. This should take about 8 weeks, so be patient! When you are able to cut for the first time, you will want to make sure you follow good cutting techniques and mow high.

What are Proper Mowing Techniques?

Once you have managed to grow a great looking lawn, you want to keep it looking that way. Following the hints below to keep it looking healthy for years to come:


  • The number one rule to remember when mowing is to keep a sharp blade! Keep in mind that you should get your blade sharpened after every 20 hours of work. Most hardware stores can do this for you for a minimal fee, and it’s definitely worth the effort since a dull blade can rip even healthy lawns up by the roots, and decimate new growth completely.
  • Move slowly and turn gently to avoid ripping up new seedlings when mowing in new areas of growth. Their roots are still growing and will not have anchored the grass stems to the soil as strongly as matured plants.
  • Try to mow only when the lawn is dry, and not following a rainstorm, or watering session. Wet grass can become torn and tangled, leading to being pulled up by the roots- something you obviously don’t want to happen.
  • As mentioned -mowing high so you don’t disrupt the root system, and following the ⅓ rule to encourage a thick, lush lawn, generally will ensure a healthy life and look to your grassy areas. The perk of these rules often becomes that you don’t have to mow as often as well.
  • Try to leave behind your grass clippings as long as they aren’t clumping. They will return nutrients to the soil, and help retain moisture without adding too much to the thatch. However, if seeding weeds were present, your best option is to bag your clippings and dispose of them within a compost, or far enough away from your lawn to avoid re-seeding the weeds.

Ready to Mow?!

Chances are if you’ve seeded a bare patch, or overseeded existing lawn, you have had some questions concerning what step comes next. Keep in mind that patience both with the growth of the new seedlings, and its maturation, is crucial to overall lawn care and health before you prep that lawn mower.


  • Be sure to become familiar with the particular type of seed you have spread.
  • Familiarize yourself with watering techniques to help keep the top 1 inch of soil moist during germination and early growth.
  • Don’t prep that lawn mower until the new grass is at least 3 ½ inches tall! This will most likely take at least 8 weeks or more after germination!
  • Apply the ⅓ rule, and cut high to encourage deep roots, a technique that is not only great for new growth but existing lawns as well.

I hope this was a helpful article, and if you have any further tips to share or questions, please comment below!