Question
mY bEGONIA HAS A MOLD GROWING ON SOME OF THE LEAVES AND ON IT'S STEMS.  tHE LEAVES HAVE A CIRCULAR PATTERN ABOUT 1/2 INCH LARGE.  wHAT CAN i DO TO SAVE THIS PLANT??

Answer
Ron,

Your begonia is getting mold because you are keeping it too wet and the soil is too heavy. Most potting soil is a mix of peat moss, top soil and perlite, with very little perlite. The peat moss holds water for a long time making weekly watering during these short winter days unnecessary. When you are watering plants pick them up to see if they are heavey, if they are they do not need watered. If they are light it is time to water. Keeping a plant constantly moist causes mold growth lie you are experiencing and can cause root rot. If you can do anything to drain excess water from the plant such as remove the drain tray and let the plant sit in the sin overnight to drain that will help.  Also take a can of aerosol Lysol type spray and hold the leaves apart and spray the affected areas being sure to hold the can at least 6 inches from the plant so the spray is not too concentrated in one area. Spray all affected areas and respray weekly till the problem is totally resolved. If the plant is extremely bushy you might remove some of the most affected stems to thin it out and get more air circulation through the plant. I would also move it to the sunniest location possible. Mold doesn't lie the sun.

Next time you repot this or any other plant buy an extra bag of perlite (little white pellets) and mix it with the potting soil at a ratio of 2 parts soil to 1 part of perlite.  Your plants will love you for it as the soil will be a lot lighter and the roots will breath better and they should not hold so much water and get so easily overwatered. Good luck.

Darlene