sutartsorric writes
On the same subject, would duckweed discourage frogs?

Too much duckweed can stop the pool from warming up and thus delay the
growth of the tadpoles.

My pond is covered in it now and I have given up clearing it because
there is too much and it multiplies so fast that it has recovered the
pond again in less than a week. I used to have frogs but haven't seen
any recently and I wondered if the duckweed is the reason?

Frogs spend most of the year foraging in amongst damp vegetation - they
certainly don't live in the pond all the year round, although some of
them do hang around the pond during the day. I've currently got about a
dozen frogs hanging around the edge of one of my ponds, and I'd guess
there is no more than another dozen actually in the pond - whereas at
the peak of the breeding season I'd expect over a hundred. So I 'd
guess that your frogs are maybe just doing their usual thing and hunting
elsewhere in the garden.

It's difficult to clear duckweed at the moment if you have newts - the
newt tadpoles are still tiny (they hatch much later than frogs, and any
scooping of duckweed gets a lot of newt tadpoles too.

--
Kay