How soon to breed a mare after she delivers?

Technically, a mare can be bred again on her "foal heat". Her first "heat" cycle usually a few weeks after giving birth. For big breeding farms they do rebreed the mare at this time. For most backyard horse people this time comes and goes without notice. They are too busy playing with their new foal and its nice for the mare to recover from birthing. There is usually plenty of time to decide if you want to breed your mare again.