I'm sorry but what you have doesn't seem to really count as a pond and may be too deep for a bird bath. But I may be overstating the case. Do the birds come to drink?

Depending on how deep it is you can put in some water hyacinth, water lettuce, water lily and some grasses. You'll probably want to put some rocks or something for the birds to stand on to drink. Will you be putting the feeders near it? A pond pump to move the water around would be best but rain will help. The plants will keep the water somewhat clean. You may want to do some partial water changes every couple weeks.

thank you!!!!!!!!!!!!!!

Most marginal water plants will do well in that set-up. Water lilies require a deeper set up but maybe a pygmy variety might do OK. Word of warning though....this could lead to a water addiction till your garden is like mine - 3/4 water front and back. :-)

AGuy has great advice for you. He covered all the bases. I use water hyacinth and also love fairy moss. They both reproduce quickly and cover the water. Plus the water hyacinth is so beautiful when it blooms.

Hahaha Holly is right on!!! Ponding can become so addictive and is so rewarding. Small sandbox pond this summer, next spring? who knows.

Right now I'm debating on how to add a small water feature to a little garden area I'm planting. It may turn into a pondless water feature with a stream.

A pump that sprays water vertically at least 4' will attract hummingbirds. Or a water mister where the water falls down. They love to hover in the spray. That might work for your sandbox pond as long as the water gets topped off on windy days.

A large flat rock with some mud on it will attract butterflies.

Have a great time with your birdy pond however you set it up. I love watching them bathe in my stream.