Return to the Lawn Care Forum | Post a Follow-Up

Exisiting grass too tall for new grass?

Posted by adscl84 SE WI (My Page) on
Tue, Sep 17, 13 at 16:08

Immediately prior to slit seeding my yard (appx. 1 week ago), I cut the existing lawn to about 1.5". Something tells me I should have gone shorter, but I was afraid of going too short, as I've been mowing at 3" all year and the grass was probably about 3.5-4" when I cut it.

I can already see some sprouts (very few) growing where there is no grass around, but the existing lawn is growing fast and I'm afraid it might prevent the new seed from growing.

Could I cut the existing grass down again -- before a lot of sprouts come up -- without doing much damage? Or am I be better off leaving it alone?

Follow-Up Postings:

RE: Exisiting grass too tall for new grass?

I'm not one of the experts on here but I would think the mower would blow your seeds and it would be counterproductive to establishing good soil contact. If I were you, I'd wait until your new grass is rooted.

RE: Exisiting grass too tall for new grass?

I agree, leave it alone. There is a trade-off when overseeding into an existing lawn. Some sprout and you lose some. Mow when the new grass is 3 inches high.

RE: Exisiting grass too tall for new grass?

In the larger bare spots (appx. 4 sq. ft.) some of the new grass is just under 2" tall, some of it has just started poking up through the dirt, and some of it is inbetween.

Which of these should be 3" tall when I mow? I can't really tell how tall the stuff within the existing lawn is. The existing lawn is at least 5" tall now.

RE: Exisiting grass too tall for new grass?

Mow the tall grass and avoid the areas where the new grass predominates. When it gets to 3 inches, mow it back to 2. The tightrope you are walking is to avoid breaking the new grass (under 1 inch) and still allow enough sunlight down into the new grass so it will take root.

RE: Exisiting grass too tall for new grass?

Thanks for the help. I mowed to just under 4" and maybe the grass wasn't quite as tall as I thought in most spots. Sometimes I felt like nothing was getting cut, but some of it was easily 6"+. The grass felt super plush when I walked on it, so I'm hoping I didn't do too much damage because I would love to keep it like that.

I've watered lightly twice a day for the last two weeks and decided to back off to a slightly heavier watering once a day now that it looks like most of the grass that sprouted is at least 1". When should I stop doing that and start the "deep and infrequent" watering again? After the first mowing of the new stuff?

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Lawn Care Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here