Things You'll Need
Lemon juice
Scrub brush
Garden hose
1-gallon bucket
White vinegar
Water

A cement bird bath is a nice addition to your yard or garden and will attract a variety of wild birds to your yard. Cement bird baths are sturdy and last a long time, providing a place for birds to drink and cool off on a hot summer's day. Over time, you'll notice colorful mold growing in the bottom of your cement bird bath as a result of standing water, dirt and bacteria. Keep your bird bath looking nice and maintain it as a healthy place for wild birds by removing mold whenever it appears.
Step 1
Pour out any water in your cement bird bath. Fill the bird bath with straight lemon juice. Lemon juice is a natural mold killer.
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Step 2

Allow the lemon juice to sit in your cement bird bath for 10 minutes. Scrub the bird bath with a scrub brush to loosen and lift mold. Rinse your bird bath well with water from the hose.
Step 3
Tackle remaining mold stains in your cement bird bath using a solution made of one part white vinegar and four parts water. Fill the cement bird bath with the diluted vinegar solution and allow it to sit for 15 minutes.
Step 4
Work the vinegar solution into the mold stains by scrubbing it with a scrub brush. Pour the vinegar solution out and rinse your cement bird bath for a few minutes using the garden hose.
Step 5
Prop your cement bird bath up against a tree and allow it to completely dry before filling it with fresh water.
Tip
Use straight vinegar for stubborn or old mold stains on a cement bird bath.
Warning
Bleach can be used to remove mold from bird baths but must be removed thoroughly, as traces of bleach will kill the birds.