Will mowed off Kentucky Blue grass seed heads improve the lawn?
When the seed heads are mature, is it good to mow (without a catcher) to help spread the seed and thicken the lawn?
Larimer County Colorado
If you wait until the seeds are mature (brown and hard) and "mulch" them into the turf, you can get some germination. However, if you want to overseed a thin lawn, you're better off aerating it heavily and then overseeding with purchased bluegrass seed from a seed store or garden center. Depending on how old your lawn is, the "common" types of bluegrass don't produce the highest quality of turf and tend to be the ones that produce the greatest seed heads. In short, probably not the grass you really want to overseed with.
Bluegrass seed is fairly inexpensive (about $5-6/pound) and the germination rate, quality, durability and drought resistance will all be greater with improved seed varieties.
In general, it is always best to return clippings to the lawn (don't use your bagger), as this keeps fertilizer in the system and improves turf quality. It also adds to organic matter to the soil and does not add to thatch.