My concrete steps are becoming black,how do i clean them,please

Bleach and a good scrub brush is the least expensive method.

try simple green in bucket of water and a scrub brush. I used to have a scrub b

thanks cat....I used to have a scrub brush that would screw onto long broom handle. Works great.

I recommend a power washer. My concrete patio was the same way and a power washer did the trick.

Pressure clean or bleach.

bleach scrub hard you have mold growing

The most efficient & easiest way is with a power washer. You could use bleach/water mix & scrub, but the bleach could kill any nearby plants/grass. I love my power washer..fast & convenient.