What do you think? What is your experience?
Is is possible to seed (or overseed) a lawn and apply crabgrass control late enough for the seed to survive AND yet early enough for crabgrass control?
In theory, there should be a skinny window between the time the newly seeded grass comes up and the date before crabgrass emerges. The manufacturers and universities will not talk about this--perhaps because--it is contrary to the label.
For the liquid, it says something like: apply to turfgrass that is well established and has developed a good root system, good stand and has received at least two mowings.
I could not find anything about seed on the label of the dry Dimension mixed with fertilizer, except it mentions use on "established lawns". How established? Is that a matter of opinion?
I tried appying dry Dimension to containers of new grass at 23 days old. There was no injury. On the other hand, grass that was 7 days old and about 2 inches tall was injured. It was late summer. Moisture and soil temperature were nearly ideal for rapid germination.
Clearly, ryegrass or tall fescue has a chance to be strong enough, but...Kentucky bluegrass is probably too slow, fine fescue I am not sure. Bermuda seed would not emerge till later of course.