December 2020 Culture, Variety Info

Culture Report: Begonia Double Delight Series By John Gaydos

When we think of shade-loving flowering annuals, begonias are almost always one of the first plants to come to mind. There are over 1,200 species and 15,000 hybrids of begonias known to begonia experts and gardeners worldwide. Begonias have been recorded in horticultural journals since the late 1600s. They range in size from tiny miniature forms barely 3 inches tall to large-leaved varieties that tower 5 to 12 feet over the garden.

Due to their diversity, begonias have intrigued breeders around the world — and those breeders have made massive improvements to the subsequent hybrids. Whether that be increased color range, greater petal substance, more disease tolerance or even the ability to expand into brighter sections of the garden, these are benefits that all gardeners can appreciate.

Proven Winners is very proud to bring ‘Double Delight Blush Rose’ and ‘Double Delight Primrose’ to the gardens of North America. The path to these two new introductions has been long, both in the breeder’s development and in our trial process. Today’s gardens are often a mix of light levels — some full sun, some with barely an hour’s worth of sunlight penetrating the heavy shade. And the gardener’s time is usually limited, which means soil moisture levels often fluctuate. In order for the gardener to succeed, a new introduction must be able to thrive under these conditions. Plant tidiness and uniqueness are also important factors to consider.

Ultimately, garden performance is utmost on our list of requirements for any introduction, but we also must be mindful of the producer’s success, retail longevity and shelf appeal. In order to build consumer acceptance, the gardener has to be able to readily find these begonias and, once purchased, be successful in their cultivation. We have met all these goals with this introduction. The plants are easy to grow and make a great retail presentation. The flowers last a long time on the plant and the retail maintenance is minimal.

FEATURES AND BENEFITS

Double Delight begonias bring an abundance of cascading flowers to the garden, whether in containers or the landscape. The flowers are not only fully double, but also aromatic with a softly citrus fragrance, covering a canopy of olive green foliage. The plants are more vigorous than comparable varieties with better branching power and increased flower counts. Another important benefit is sun tolerance. While still great in the shade, Double Delights handle full sun just as well.

GROWER TIPS

• Extended photoperiod for flowering; for all tuberous begonia varieties, long days are needed to ensure the best foliar growth and even flower production. If the liners are planted before April 1, 14-hour days are needed, and at least 12-hour days for those begonias planted later.
• Warm, slightly dry soil (70 to 75° F) will speed the rooting-in process.
• Avoid placing any plants over the crop of Double Delights, and keep the foliage dry, especially in the afternoon.
• Begonias must have good air circulation and humidity control.
• A good sanitary protocol will keep the foliage disease free.
• Treat with a preventative broad-spectrum fungicide, and drench two weeks after transplant.
• To control stretch or to hold plants for a delayed spring, 150 to 200 ppm of a Cycocel spray can be used.

GARDENING TIPS

• Plant in full sun to full shade. Use well-draining soil.
• When building hanging baskets or larger combinations, plant the Double Delights with the stems pointed toward the outside of the container. The flowers will follow the direction that the stems and leaves point.
• The thickness of the stems and the fleshiness of the foliage is a water buffer for the begonia; do not over water the soil to the point where it is wet or soggy. Keep the soil dry to moderately dry, especially during the first few weeks after planting.
• Great companion plants for the Double Delight begonias are Diamond Snow euphorbia, Snow Globe or Snowstorm sutera, Hippo hypoestes and the Endless browallia series to name a few.