SOIL: Begonias prefer acidic, well-drained mix.The peatlite mixes do quite well for Begonia culture.
LIGHT: Rex Begonias will grow best at light intensities between 2,000 footcandles (FC) and 3,000 FC. Best growth will be achieved at 2,200 to 2,500 FC. Additional shade may be required during hot periods of summer.
FERTILIZERS: Begonias are not heavy feeders but do require a constant source of nitrogen. Run 100 ppm nitrogen (N) form a 3-2-1 or 2-1-2 source, such as Peters 20-20-20. Check your soluble salts regularity to insure that TSS do not exceed 1.2 Milimhos.
TEMPERATURE: Maximum day temperatures should be 90°F with minimum night temperatures of 60°F.
WATERING: Begonias require constant moisture; however, if you keep the soil saturated, Phythium and Phytophthora may result.
GROWING TIMES: Growing times will vary with greenhouses conditions; however, the following may help in planning your first crop:
|Estimated Finished Time|
|1 liner 4” pot||6 to 8 weeks|
|2 liners 6”pot||8 to 10 weeks|
|3 liners 8” BP||10 to 12 weeks|
|3 liners 8” HB||10 to 12 weeks|
|Add one more liner per pot to reduce growing time by 2 weeks|
WATCH FOR: Mealy bugs, aphids, thrips and caterpillars are the major insect pests of Rex Begonias. White fly sometimes becomes a problem. The major disease problems of Rex Begonias are Botrytis and Powdery Mildew. Myrothecium also causes a leaf spot and petiole lesions. Good air circulation will help in the control of some of these diseases.
CULTURAL NOTES: When light intensities are lower than optimum, some stretch will occur. This can easily be controlled with application of Arrest 50 ppm.