Starting strong

Greenhouse Management: Would you recommend that a grower start their begonias from seed? What would be the most important cultural requirements to address? Humidity? Light requirements? Temperatures?

Ulrike Bubner and Diro Terefe-Ayana: Begonias need very high humidity. Begonia pellets need to be completely saturated for the first 10 days to provide enough moisture to crack open or melt/dissolve the pellet, allowing the radicle to emerge. Humidity needs to be 95-100% during this phase. Many professional growers cover their newly sown trays with translucent plastic to keep humidity high. The duration of covering with plastic varies from grower to grower.

Always be sure to provide enough moisture/humidity to crack/dissolve/melt the pellet during the 1st 10 days. Provide light source (minimal is sufficient) if using a germination chamber. On day 11, it is crucial to increase horizontal airflow and dehumidify to 40-60%. Growers will want to be sure not to use too much water volume/pressure during these stages which can dislodge or bury the tiny seedlings.

Begonia like warm conditions. Some growers use floor heating. We also recommend using warm water for irrigation to minimize stress to the young seedlings.

GM: Are there certain species that might be easier to grow from seed than others?

UB and DTA: To our knowledge, there is no obvious difference in the handling of seeds between different Begonia species. However, there exists some variation in the uniformity of seedling development between tuberous Begonias and fibrous Begonia. For example, Begonia semperflorens make more uniform seedlings compared to Begonia tuberous.

All of Benary’s begonia species pellets are very similar and should require the same basic protocols for germination. Begonia tuberhybrida, Begonia boliviensis, and hybrid interspecific series, like the Funky Series, all require long days (recommended 14 hrs.+) and warm nights (recommended 65° F) throughout production.

GM: Do you have any tips or tricks that would help a grower get started growing their begonias from seed?

UB and DTA: Growing Begonias is not for beginners. The first challenge is the sowing. Begonia seeds are very small and hard to handle. Usually Begonia seeds are sold as pelleted seed. There are several important advantages for using pellets: seeds are more visible; uniform sowing is guaranteed; and pelleted seed is easier to use in mechanical seeders.

Benary’s Seed Technology Department is continually using research to create new recipes for the most state-of-the-art pellets for every crop, including Begonias. Because of this Seed Technology, Benary seeds will typically germinate better and provide more usable plants for the grower compared to other suppliers.

“Rough sowing” or sowing by hand is possible. When sowing by hand, proper precaution is needed not to pour masses of seeds on the sowing tray at once. Without adequate spacing, the germinated seedlings intermingle and can be difficult for transplanting. Proper planning of the right time for sowing and transplanting is essential. Growing begonia young plants is an art form that is only developed after several years of practice. The cultural practices and nutrient combinations provided for seedlings will determine the quality of young plants.