Do you spray new topsoil before planting grass?

[summit151]

Hello so I recently killed my entire lawn and used a soil conditioner to smooth it all out. But I had to bring in a bunch of new top soil to make sure I had adequate depth of soil
For my new lawn. So this top soil was 12 year old cow manure that looks and feels just like black dirt. So my question is do I have to spray this all again before applying seed? If I do have to what kind of spray? Would I use round up that kills everything or just a weed control product ?

Thank

 

[Oldoak]

What are you trying to kill if there is nothing growing in it? Spray it with a pre-emergence chemical and you will never see new grass. Spraying it with Round-up would be a total waste of money. It only kills plants that have sprouted and are growing.

Many weed varieties will remain viable in the soil for years and years. However, being the cow manure is like black dirt, mostly likely the majority of any hay and weed seeds that were in it have been killed during the natural composting process.

 

[Industrial Toys]

My Dad, ever trying to get stuff free, once got cow manure from our farmer here for his suburban lot. Talk about industrial strength thistles!

I just planted quite a bit of new grass. Yes, in spots weed and unwanted types of grass are growing among the new grass. It just depends how fine a lawn you want.

Should one let the new grass grow to seed, or cut it like normal grass height and just let it spread? Does grass seed not covered by soil grow? I would think not, but how does the natural process work? Sorry to hijack.

 

[Streetcar]

Mowing new grass helps control weeds and stimulates root growth
As old oak said do not spray bare dirt

 

[Norm W]

Just wait till something comes up green and mow it. I mow what ever grows, the neighbor does weed, feed, etc.. Come the dry part of summer my yard is green and his is brown. I cut close because I hate mowing, in fact I try to kill the lawn. The stuff stays green and grows to spite me.

 

[Industrial Toys]

So, on a newly planted lawn, that may be sparse in spots because dragging after spreading seed isn't perfect, how does the lawn fill in?

 

[John Fitzgerald]

Any time I ever got manure, I got lots of pigweed, dock, lamb's quarter, plantains, etc. If you want a weed free lawn, you will have to spray broadleaf killer relentlessly after the new grass comes up, or put down pre-emergent and then sod the lawn.

 

[mercdv]

Do not spray it. As some have already pointed out that if you spray it the new grass won't grow. When planting new grass you will always get some weeds that show up. The idea is to keep the grass healthy enough to choke out the weeds. When the grass is healthy enough (typically after several months) you can kill off any weeds that survive but if you spray/treat too soon you will kill the immature grass as well. Start it growing and then follow the recommended mowing schedule and height for the type of grass you are planting. They usually have pretty specific guidelines for the first 4 mowing cycles on new grass and it is based on type of grass and season. Be patient, establishing a new lawn takes lots of patience. Don't forget to try and pull weeds by hand when you see them in the early days of the new lawn if the yard is small enough. The other advice I will give is to water DEEP. You want those roots to get established deep while the lawn hasn't been compacted yet. The roots need to chase the water down 3-4 inches into the soil (or some other depth depending on grass type). This will help your lawn fight disease and keep it healthy enough to choke out weeds.

If you want to be a perfectionist about it, you should test soil samples before planting the grass to make sure the soil will support the grass you are planting. Your county extension office should be able to test it for free, at least ours does.

Good luck....hope it all goes well.

 

[GLyford]

Use a "starter" fertilizer, it helps form deeper roots than the regular "feed" rated stuff.