Gardening Articles: Flowers :: Bulbs
The Begonia Show-Offs (page 3 of 3)
by Chuck Anderson with Laurel Taylor
In any climate (except the desert), winter storage of dormant tubers is important to their success year after year. Jack Babiash of Green Bay, Wisconsin, has grown 50 to 60 tuberous begonias annually for a decade. His tubers spend the winter on a table in his basement until mid-March. Eschewing some growers' practice of using artificial lights to start early growth, Babiash still enjoys three summer months of cheerful color following the plants' natural calendar.
Tuberous Begonias Calendar
February/March: Time to Plant
Once pink growth buds appear atop stored tubers, plant tubers concave side up and rounded side down in nursery flats or pots filled with moistened, well-drained leaf mold or coarse compost, then lightly cover the tuber with about 1/2" of the same mix. Place flats in a warm (70 degrees F.) room out of direct sun. Water to keep the soil moist but not soggy. Keep the plants indoors until all danger of frost has passed.
After the last frost in your area and when plants reach 2 inches tall, transplant each to its own pot or basket with the tuber lightly covered with about 1/2-inch of potting soil or, in the ground, with soil amended with at least one-third compost. Place them where they'll receive filtered sunlight, light shade, or morning sun followed by afternoon shade. Eastern and northern exposures are best. Fertilize every two weeks with a half-strength solution of fertilizer (approximately a 3-1-2 formula).
May through June: Showtime!
Tie upright plants to stakes. Watch for fuzzy white spots on leaves, signaling powdery mildew. If you see the white spots, spray foliage with a fungicide labeled for powdery mildew on begonias. Continue to fertilize (at half-strength) every two weeks or so, and water to keep soil moist but not soggy. No pinching or pruning is necessary.
September or first frost: Plants fade.
Bring outdoor plants into a well-ventilated, dry, and shady place. Withhold water, but don't remove faded stems until they drop off. Once the plant is gone, dig out dormant tubers and rub them gently to remove clinging soil; dry in the sun. Label the plants, noting flower color and whether upright or hanging-basket plants. Store dry tubers in egg cartons (or in a box but not touching each other) with their labels. Store them in a cool (40 to 55 degrees F.), dark place, and check them monthly to remove any soft, moldy tubers.
Chuck Anderson--the Santa Cruz, California "Garden Guy" and past president of the American Begonia Society--grows tuberous begonias in Rio del Mar. Laurel Taylor is also a tuberous begonia enthusiast based in Santa Cruz.
Photography by Netherlands Flower Bulb Center