A reader wants to know how to remove these leaf stains from concrete. (Reader photo)

Q: I found your Dec. 3 advice about removing rust stains from concrete pavers to be quite interesting. I have a problem with stains on concrete, though not from rust. We recently put down a concrete walkway in front of our house. As the leaves fell, especially in the rain, they got stuck to the pavement and left unsightly brown stains. We have tried hosing, bleaching and scrubbing, but we can’t remove the stains. Do you have any suggestions?

Rockville

A: The leaf stains are caused by tannins, the same type of compounds that are found in grapes and make wine taste “dry.” Tannin stains on outdoor concrete often go away on their own, thanks to the powerful bleaching action of the sun. But if you don’t want to wait, try using OxiClean — the basic product, labeled Versatile Stain Remover. It’s carried by most hardware stores; at Lowe’s, an 80-ounce tub costs $10.98.

The active ingredient in OxiClean is sodium percarbonate, a powder that, when mixed with water, releases hydrogen peroxide and soda ash. They are the actual cleaners, assisted by the bubbling action of the hydrogen peroxide.

First sweep the walkway and hose it off. Although it’s possible to scatter the OxiClean powder on the wet concrete and then scrub with a stiff broom, you’ll probably get a more uniform result by mixing the powder with water first. Use four scoops of powder per gallon of water. The powder mixes best into warm-to-hot water. Mop that onto the walkway and wait five to 30 minutes. During that time, you can scrub the concrete to make the cleaning more effective. The solution shouldn’t dry on the surface, so add more as needed to keep the surface damp and avoid tackling too big an area at a time. Finish up by rinsing with plenty of water. The runoff shouldn’t hurt plants.

Although pictures on some OxiClean packages show what appear to be bare hands at work, wear rubber gloves and take care so you don’t get any powder or cleaning solution in your eyes.

I inherited a marble tabletop with rust-colored stains. How do I remove them?

Arlington

Most rust removers are acidic. Because acids etch marble, limestone and travertine, labels on rust removers typically warn against using them on these soft, calcium-based stones. Some people still use them on marble, but it’s usually a two-step process. First they get rid of the stain. Then they polish away the etch marks — not a task to be done by hand.

One exception is Lithofin Rust-EX, made by a company called Lithofin in Germany. Rust-EX is acid-free, so it won’t take the shine out of even highly polished marble. You brush it onto a dry surface, watch it turn purple and wait five to 10 minutes — no longer. Then you dribble on a little water and a bit of dish soap, and wipe and rinse it off. Rust-EX is available from mystonecare.com for $19.95.

It’s likely that some stain will remain after the first treatment. If so, you can repeat the process. The Marble Institute of America, a trade group, warns that rust stains are especially difficult to remove.

If your efforts don’t succeed, you may want to call a pro who installs and repairs marble countertops.

Have a problem in your home? Send questions to localliving@washpost.com . Put “How To” in the subject line, tell us where you live and try to include a photo.