When to mow after overseeding?

[Baike]

There is a lot of information suggesting to mow when new grass is 3" height.

But my situation is: I planted grass seed less than 10 days ago, some for bare spots, some for thickening existing lawn. I take well care of it by watering multiple times throughout the day, overall, the outcome is fine to me. Some grass seed sprouted in only 4-5 days and is already 3" tall, while I believe some grass seed has not germinated. Part of reason that they germinate at different date: sunlight & soil quality. Yes, the soil in some area is rich and while it is poor in some other area.

Now some grass needs mowing badly (particularly existing lawn), but in-between existing grass, there is new small grass, will mowing damage new grass?

Thanks.

[Hemlock140]

The young grass can handle the mower wheels and spring back. The problem is that until their are enough blades and roots the soft soil is subject to ruts from the mower wheels. If possible, the best thing to do is walk only on the old lawn and use a string trimmer to mow the places where you can't safely use the mower.

[Baike]

Originally Posted by Hemlock140

The young grass can handle the mower wheels and spring back. The problem is that until their are enough blades and roots the soft soil is subject to ruts from the mower wheels. If possible, the best thing to do is walk only on the old lawn and use a string trimmer to mow the places where you can't safely use the mower.

Oh, I was thinking about using mower grass catcher bag, so that the grass won't fall on the lawn.

Using string trimmer won't be able to catch grass.

[CaptainNJ]

i just did a bunch of overseeding like you for filling in and thickening. it looks like some areas had great results and some not so great. i gave the guy 2 weeks off from mowing and told him to start again this week so the grass wouldnt have been mowed for 3 weeks. the existing grass is getting too long for me to handle. im looking forward to getting a better look at the results after.

[Hemlock140]

Originally Posted by Baike

Oh, I was thinking about using mower grass catcher bag, so that the grass won't fall on the lawn.

Using string trimmer won't be able to catch grass.

The cut grass on the lawn won't hurt it, in fact this time of year it will decompose and help fertilize the new grass. That's why I use a mulching mower.

[Cambium]

Originally Posted by Baike

There is a lot of information suggesting to mow when new grass is 3" height.

But my situation is: I planted grass seed less than 10 days ago, some for bare spots, some for thickening existing lawn. I take well care of it by watering multiple times throughout the day, overall, the outcome is fine to me. Some grass seed sprouted in only 4-5 days and is already 3" tall, while I believe some grass seed has not germinated. Part of reason that they germinate at different date: sunlight & soil quality. Yes, the soil in some area is rich and while it is poor in some other area.

Now some grass needs mowing badly (particularly existing lawn), but in-between existing grass, there is new small grass, will mowing damage new grass?

Thanks.

The different germination times could be simply the different type of grass.
Don't be scared to walk on it but don't dance or make a pivot on it either.
Let the grass clippings fall onto the ground. No need to bag. They will help keep the soil and new seeds moist as well as the other benefits.

[Baike]

Will mower (grass catch bag) suck in grass seed(which has not germinated)? I think some grass seed sitting on the top of soil, I did not use enough top soil.

[NC211]

I have always given it 2 weeks, just skip a week, and have never had a problem. I don’t think you’ll suck the new seed as much as you’ll disturb their chances of germinating and getting roots into the soil if you don’t give them roughly 10-14 days of not being disturbed.