In article e65e9c42-b139-40d1-891c-22af83c57631
@m36g2000hse.googlegroups.com, says...

I got some horse manure, aged, that gave me so many weeds in that
garden that I am loathe to use it again. What do you do about that?
Nan in DE


I'd probably incorporate it into a compost pile that's built to heat up
fast and stay hot long enough to kill the weed seeds.