6 or 7 inches in a month?!?!?! I have a hard time believing newly seeded grass can get this tall in a month's time, and even sod takes a bit to get going again after it's been harvested and laid. If this is in fact the case (measure your grass to be sure) then unfortunately you waited far too long. Newly seeded tall fescue usually gets its first cut after about 3-4 weeks or when it reaches 3 inches. KBG is about the same, cut it when it reaches 3 inches. Since your grass is 6 inches I recommend you mow it to about 4 ASAP, then in a few days mow again down to 3, bagging your clipping for those two mowings. Then in about a week I would cut it to 2.5 inches.

I don't know why you waited too long, but this is something you can get back under control fairly quickly. We've got some favorable weather coming up early next week, so get started as soon you can; you'll be looking good on Thanksgiving Day (next Thursday). Call me tomorrow after 9am, and we'll get you back on schedule. A few things are very important with your first cut: 1. Your mower blade must be sharp; if it isn't, then get it sharpened. 2. Set your mower deck as high as you can. 3. Collect your clippings; don't allow your clippings to stay and lay on top of the new grass. 4. Mow your new grass when it is DRY! (after lunch time if possible). I am just north of Durham, NC and I just seeded several lawns 3 weeks ago, including mine. Call me if you'd like.

Neal
(919) 699-9847

Thanks. Actually I meant what does it mean that I waited too long? What's the harm in the grass being this long? Is it that the energy is being spent growing up/longer vs being topped off to encourage root development?

Newly seeded grass should be cut at the height recommended by the grower. Generally it is 3-3.5 inches. This promotes tillering/thickening, and "trains" your grass in a way. When grass gets longer and longer it stops looking like a lawn and starts looking like a field. Ever see a field that has been cut back to a couple inches? It doesn't look anything like a lawn since you are mowing stems and crowns at that point, not blades. At what height are you planning on keeping your lawn? When you mow you shouldn't remove more than 1/3 of the blade. If you are going to keep it at 3 inches, then you should cut it when it gets to around 4.25 inches or less. Cutting your grass is a stress on it, it is much more stressful to cut 7 inch grass back to 3 inches than it is cutting 4 inches back to 3.

I'm surprised this question gets asked so often. tiemco is right. New sod or seed can be mowed any time it is tall enough to mow. For northern grasses, 4 inches is a good time to mow. Many people make the mistake of mowing at 2 inches or less. For new sod or seed that could be a disaster.

ok, thanks. I wonder why my lawn guy is hesitant to cut it? He doesn't want the sod to "flip up" if the roots aren't firmly established yet with the ground surface.

hmmm...you have a lawn guy? And he allowed the turf to get that tall before the first cut??? WOW!!! Anyone in lawn care should know that when you can pull on pieces of sod and they don't pull out of the ground, then it is ok to make that first cut. If the sod pieces become detached from the ground when you pull on them, then it's not ready to mow. Can't be any more simple than that.

Is your lawn guy using a push mower or riding mower? Is the sod on a hilly surface or more of a flat surface? I'm not sure I could justify not having made the first cut on sod already. Just my opinion.

Neal

It's on a sloped surface. And yes, the reason he hasn't mowed is maybe something about edges that turn up in some spots. So the blades may be long, but the entire batch of sod may not be fully attached yet. It has been 4 weeks.

Oh, and in the back a (big) push mower is used. I think he does riding mower in the front. I really haven't paid attention, but I know a riding one won't fit into the back. I think maybe he needs to use a small lightweight mower on the highest setting?

I really don't want to micromanage this (that's why I have lawn service) but the grass is too damned long and I just want it to be ok.

Being so high I wouldn't cut it in a normal height fashion because the blades might grab too much and pull the young grass out. Cut it in 2 or 3 stages, removing a little at a time but do cut it back to about 2 1/2" - 3".
If you have normally cut a lawn back short before winter, I advise you not to do that this year, let the new lawn set down good roots.

I apologize if I seem too critical, but I just know that proper timing of all turf maintenance tasks is necessary for having an attractive lawn.