About 3 weeks ago I put down some grass seed and covered it with seed matting. The grass is coming up really nice but there's also weeds coming up. So my question is when is it safe for me to put down Scott's turf builder weed and feed? I spent a lot of time and money on grass seed, seed matting and I rented a tiller to turn over the soil before putting the seed down so I don't want to risk killing the new grass that's coming up but I don't want the weeds to takeover either. Need advice from lawn experts, thanks

What kind of seed did you use? Sounds like the weeds were introduced with the planting (my dad had the same prob paying a landscape company to do the same thing you did).

You should wait until the new grass darkens to near normal green so that it's got a good root base. In fact, I wouldn't mow it until it does so let it get 12-16" tall first (might have to knock back with a trimmer if your mower bogs down).

2-4D

I usually wait until all the seed is up and then until first mowing.

Then I apply weed killer and new grass fertilizer, not full strength fertilizer.

quote:

Originally posted by Patriot:
I usually wait until all the seed is up and then until first mowing.

Then I apply weed killer and new grass fertilizer, not full strength fertilizer.

Mostly agree. I just usually wait until second mowing.

The starter fertilizer has lots of phosphorus for the roots while the regular four-step usually has none. There’s no harm in waiting, the weeds can be taken care of later.

It says on the bag that now would be too early.

I would let it go another month or two to be safe. Weed growth should not be out of control by then and you should be able to kill them off with no issues.

I had the reverse problem. I put down crabgrass preemergent and tried to plant grass too soon afterwards. About half did not take.

Don't cut the grass too short either. Especially this time of year as we could get dryer and hotter weather. Just be sure your mower blades stay sharp with the taller grass or it will tear the grass, not cut it cleanly.
That will make the grass less hardy and the weeds seem to love the dead grass areas.
2-4-D is really the weed killer ingredient in Weed-n-Feed and a generic version is less expensive.
If it was my lawn, I'd wait until late summer to kill the weeds with chemicals, when the grass is more established.

quote:

posted June 05, 2022 09:57 AM Hide Post
I would let it go another month or two to be safe. Weed growth should not be out of control by then

you must have some unique weeds then
I would spray soon. I do not care for weed n feed other than for maintenance after an effective spraying or two.