Begonia boliviensis Bonfire, which is
Stick unrooted cuttings, available from Selecta First Class, in 102- to 105-cell trays containing a well-draining growing medium with a pH of 6.5 and an electrical conductivity of less than 0.5 deciSiemens per meter. No rooting hormone is required. Mist cuttings for seven to nine days. Keep cuttings moist, but don’t overwater. Maintain a humidity level of 85-95 percent. Cuttings usually root in 12-14 days. The average time for propagation is four weeks. Rooted liners of Bonfire are also available in 105-cell trays from licensed propagators.
Once cuttings are well-rooted, transplant for finishing. Transplant cuttings into a commercial growing medium containing a wetting agent with a pH of 6.5.
Tuberous begonias are long-day plants and require a minimum of 12 hours (14 hours is best) to initiate flowering and prevent tuber formation. Recommended light level for winter and spring production is 3,530 footcandles (38,000 lux). For summer production the light level should be 3,250 footcandles (35,300 lux). Shading may be required in high-light areas during summer.
Production temperatures should be 72°F during the day and 64°F at night. Temperatures higher than 79°F reduce flower size and color intensity. Once buds are formed, finish plants at 57°F-61°F to increase flower size and flower color intensity.
Provide a constant supply of fertilizer. Apply 250 parts per million nitrogen every two weeks. A five- to six-month slow-release fertilizer with minor/trace elements (i.e., 17-17-17) can be incorporated at 2 pounds per cubic yard. Monitor electrical conductivity regularly to be sure it remains below 0.5 deciSiemens per meter. Reduce fertilizer levels near crop finish to avoid excessive foliage growth.
Don’t overwater. Keep plants spaced for good air circulation. Overwatering can lead to root rot problems and/or leaf drop. Begonias have succulent stems and can withstand periods of dryness between waterings.
Pinch to increase branching. Growth regulators are usually not required.
If grown under the right environment, disease is not usually a problem. Powdery mildew can occur when temperatures are low and humidity is high. Botrytis can also occur during periods of high humidity. Keeping greenhouses well-ventilated can help avoid disease problems.
Common insect problems include snails, slugs, aphids, whitefly and sciarid fly.
Normal production time is eight to 10 weeks grown at 60°F days and 65°F nights during weeks 8-14. Production time can be shortened by a week if plants are grown at 65°F days and 67°F nights during weeks 15-20.
For more: Selecta First Class Inc.,
Name: Begonia boliviensis
Grower benefits: Easy to propagate from cuttings. Production time is fast, and plants can be grown in a variety of container sizes.