Begonias were originally grown in Africa, near the equator where very little change in day length occurs.
If you are growing varieties of begonias in the greenhouse, there are several best production practices you need to know to ensure a successful crop. Plantpeddler’s Mike Gooder went over his top tips during a session at AmericanHort’s recent Finished Plant Conference.
“Stress management is the key to this factory. If you take away one message from this presentation, I would like it to focus on stress management,” Gooder told attendees.
Specifically, he said to reduce stress early in the life cycle of plants to get more vegetative growth initially, and then induce stress to get them to flower.
“Once they leave your spread zone, no more [supplemental] lighting,” he added. “And then you want to reduce the stress as they finish.”
Gooder also discovered the ideal planting method for begonias. He said that since begonias have a front and a back, it is important to plant them back to back, and you should always turn young cuttings so they are all in one direction, back together with two fingers spaced between them. when planting in trays. .
About pinching, he was very clear: don’t do it.
“No, you will add a lot of time to the production cycle [if you pinch], and you lose the uniformity of flowering; you don’t need to pinch,” Gooder advised. “And if your begonias stretch, bury them. Don’t be afraid to plant them too deep – you’ll get some branching below the soil line and you want stability in the pot, and this will give you that.
As for the climatic conditions in the greenhouse, Gooder said you “can’t fool the heat” with begonias.
“Begonias need all the love – they want to feel warm, to be pampered, that sort of thing,” he explained. “You want a mild environment with high humidity and average temperatures in the 70s.”
“The biggest problem I see is people cheating on the warmth of this culture,” Gooder added. “Once the outside temperature starts to drop, you induce flowering. But run them veg to at least 75-78 degrees F. You might even run them in the 80s because it’s a tropical plant. This should not be grown with petunia in a 55 degree block.
Gooder and his team at Plantpeddler also strongly recommend nighttime interruption or daylength extension, saying either will suffice. And you want to plant this crop later in the spring so you can take advantage of the naturally longer days and warm greenhouses.
Regarding fertility recommendations, Gooder and co. run what he called a mild ammonia diet at about 250ppm.
“Begonias are all water so if you want a bigger begonia just add more water,” he added, noting that the crop is not very vegetative (stage) intensive or in flower. “You want a smaller factory? Add less water.
And once you’re ready to start finishing begonias, Gooder said it’s simple: you increase watering frequency and reduce your feed ppm levels (to around 100-150 ppm) while switching from ammonia to calcium-based nutrients.
As for common production challenges with begonias, Gooder says his team will occasionally struggle with premature budding, undersized flowers and powdery mildew. Managing the growing environment, controlling sanitation and monitoring EC will go a long way to alleviating most of these concerns, he said.