Growing begonias in the tropics: Trial results from Singapore’s Gardens by the Bay

The trial gardens at Gardens by the Bay in Singapore have highlighted begonia as a great option for shade-to-sun environments in a tropical climate. Over the last two years, they have evaluated 43 cultivars of begonia from Takii Seed, Syngenta Flowers, Sakata Seed, and Dummen Orange in two different growing environments.

The outdoor full-sun environment conditions averaged day 29°C /night 25°C, daily light integral 26 moles/m2/day, natural day length of 12 hours, relative humidity 79%, and 210 to 507 mm rain/month. They also evaluated begonias under 50% shade outdoors. In contrast, their indoor air-conditioned glasshouse environment (similar to our conservatory display area) averaged day 22°C /night 18°C, daily light integral 15 moles/m2/day, with a 16-hour long day photoperiod and 87% relative humidity.

Scenes from the trials
Plugs were transplanted after 8 weeks into 30cm hanging baskets in peat with 3 plugs per pot. Ten weeks after transplanting, plants were at their peak flowering period. "The plants performed well in both full sun or shade with high heat and humidity and indoors in a climate-controlled glasshouse. Notably, plants grown outdoors had more flowers, a more compact growth habit, and smaller leaves."

Here are some of the top-performing cultivars that thrived in both in the indoor and outdoor environments:

Begonia Top Hat Scarlet – Syngenta
Begonia x hybrida

Left (indoors) Right (outdoors)

Begonia F1 Fionna Red – Takii Seed
Begonia sempreflorens

Left (indoors) Right (outdoors)

Begonia Bacio Orange and Begonia Bacio White – Dummen Orange
Begonia x hybrida

Indoors

Begonia Iconia First Kiss Hot Pink, Begonia Iconia Miss Miami, Begonia Bacio Salmon, and Begonia Bacio Sunshine – Dummen Orange
Begonia x hybrida

Indoors (cultivar names front to back)

Begonia Miss Montreal – Dummen Orange


Trial plant on display in the Flower Dome for the Tulipmania floral display

Begonia Miss Montreal – Dummen Orange

Trial plant on display in the Flower Dome for the Tulipmania floral display

This year's Breeder Cultivar Trial will be on November 22, 2023, from 1 to 6 p.m. at Singapore's horticultural show garden, Gardens by the Bay.

In 2022, Gardens by the Bay partnered with world-renowned breeder companies to host a flower trial for the horticultural industry, which was the first event of its kind in Southeast Asia.

This year's program event is aimed at both growers and landscapers, equipping them with knowledge about the latest flowering plant varieties that thrive in both temperate climates and sunny tropical climates.

"Renowned industry experts from leading international plant breeders such as PanAmerican Seed, Suntory Flowers, Syngenta Flowers, and Takii Seed will showcase their top-performing genetics. Peat and wood fiber substrates will also be demonstrated by industry leaders Klasmann-Deilmann and Pindstrup", the organizers say.

The event will take place on November 22. "The venue is the research glasshouse at Gardens by the Bay, providing an ideal setting to immerse yourself in the world of plant innovation at the trials, conservatories, and gardens."

Registration is free and open to all industry members. Register here.