How To Look After Begonias In Winter. In colder ones though its best to let the first frost cut it back. Our preferred method is to store them in individual paper bags in a cardboard box.
11302011 Throw away any begonias that look diseased or infested and treat minor problems before bringing them inside. 2172020 Choose a warm humid partly sunny indoor spot for your begonias. Powdery mildew on leaves can be controlled with Baycor.
Use the best potting mix available and add 20 perlite to lighten the mix which allows better drainage and and reduces the risk of fungal problems during wet weather.
The leaves will begin to yellow naturally at which time watering should be reduced. 10262009 Bring your begonias out from overwintering during the month of April and start planting. Once the leaves begin to turn yellowor after the first killing frostdig up the entire plant and its tuber. 11232020 Rex begonias need a high level of humidity 50 percent or more but not too much water and no fertilizer during winter.