Alan Holmes writes

When should one stop feeding peanuts to small birds.

I understand it is not safe for them to try to feed their young with
peanuts.

They've been nesting for quite a while, so you shouldn't be feeding
whole peanuts now, or, if you are, you should make sure they're in a
wire feeder so birds can't get at whole ones, they can only peck out
bits.
--
Kay