On Oct 6, 2:33 pm, "Academia" wrote:
If you use fertilizer containing weed killer they want you to put it on wet
grass and do not wash it off the grass.

But if you use fertilizer without weed killer they want it washed off of the
grass. Why? Is this fertilizer different chemically?

Thanks

Let's not make this complicated.

The "weed" part like Jim said needs to be in physical contact with the
target plant. This is usually a broadleaf. Lawn is not a broad leaf
and is not harmed. You must turn the irrigation on to simply wet the
foliage. 5 seconds will do.

The "feed" comes mostly via the roots some is taken in via the foliage
but nothing significant. The next morning when your lawn is watered
the fertilizer will wash to the ground and be picked up by the roots.

It is best to apply a weed and feed on a sunny day in the morning.
Not over 95. This will allow the target weed to absorb as much of the
kill juice as possible.