Some annual flowers just knock your socks off with their beauty. I remember a few years ago wandering through a greenhouse at White Flower Farm and being bowled over by their display of tuberous begonias. The flowers were perfect in a rainbow of colors with single and double flower shapes and some were even fragrant.
Tuberous begonias hale from the Andes Mountains. They were all the rage in the 1800s in Europe, but didn’t make it to our country until the early 1900s.
When gardeners see tuberous begonias in their full glory, their emotions are mixed between, “I must have that” to “I could never grow that.” It’s true that tuberous begonias can look messy when they’re wind whipped, rain stained, and powdery mildew infested, but in the right setting they make you look like a gardening pro.
The key is growing tuberous begonias in containers where they’ll get morning sun and are protected from wind and rain. Water from the bottom to avoid getting moisture on the leaves. For powdery mildew disease, spray with Serenade organic fungicide.
Although an annual, you can save favorite varieties each year by saving the tubers. After a light frost, move the plants to a garage and remove the shoots. Take the tubers out of the pot and let them dry for a few days. Store them in dry peat moss in a 40 degree F to 50 degree F location.
In late winter, place the tubers, hollow side up, in a shallow tray filled with light potting soil. Cover them with one inch of soil and keep moist. Once they start to sprout, pot them up.