How can I recover a concrete bird bath that has become pitted/dirty?

I used concrete patch that came in a little tub. I cannot recall the brand and couldn't find a link, but I did buy it at Home Depot. I just scrubbed the bath, let it dry in the sun, then used a putty knife to apply it. I used a damp rag to smooth it out, let it dry for a day. Viola! No leaky, ucky bird bath.

Spray paint is an easy fix. Use a wire brush to get rid of any debris, you can hand paint and seal with a clear spray paint, or just go with spray paint. Rustoleum gives good results.

http://homeguides.sfgate.com/resurface-cement-bird-bath-40931.html

As a mosaic person I would see this as an opportunity.

Put newspaper in bottom, and pour bleach, to cover at least 1/3 of bird bath. Let it sit until Sunshine is over it, and give it 3 hours remove paper dump liquid in a safe place, blast hose on it to rinse

Just wash it out thoroughly with a natural bristle brush and some dawn dish soap. Rinse well, now you are back in business!

http://homeguides.sfgate.com/resurface-cement-bird-bath-40931.html. You can buy stuff to resurface it. Or fill it with soil and plant a succulent garden