Exerpt from
Permaculture Techniques "a couple of small ponds, perhaps four feet across and 18 inches
deep. Some of them filled with about 12 inches of soil, and some of them filled with about four or five inches of soil.
A
pond that size will turn out about two hundred or three hundred frogs
about twice a summer. The tadpoles live in the
pond, and the frogs live in
the cabbages, lettuces, and mulch. They return to the pond and you must
make a place for them to get out. A good sort of pond is one that is slightly
higher than the surrounding soil level, built up and paved with stones.
We put sweet alyssum and thyme and garlic between the stones. The alyssum
trails into the edge of the
water, and the little frogs climb out on it.
Another thing you can do is to build up a little stone pile in the pond. Frogs
will drown if they can't get out of ponds, so let them have a way out.
Mosquito control is accomplished in two ways. I always put a bit of garlic
around the pond and just squeeze the bulbs out into it. That is the best. That
kills the larva. Just float off your garlic oils. It's about 100% kill. The
garlic doesn't kill tadpoles. The tadpoles eat some mosquitoes, but they are not a control measure."
Here is a pic of my small pond; fed with well water, no pump, overflows into veggie bed. Black things are tadpoles.