Garden Q&A: Tips to help a nonblooming begonia
Question: I have an angel wing begonia that is over 7 feet tall. It never blooms. Do you know why?
Answer: First off, kudos to you for growing such a large begonia! Angel wings are among my favorite types of begonias, and they are an excellent choice for shady garden areas. Since yours is so large, I'm going to assume you grow it in a container as a patio plant during the warmer months and then as a houseplant in the winter.
Angel wing begonias are a hybrid of two types of begonias. They derive their common name from the elongated, wing-like shape of their leaves. The foliage of some cultivars is mottled with white or silver spots and blotches. Flowers are often white, pink or red and should occur steadily throughout the summer months and then sporadically during the winter.
Like most other types of begonias, angel wings thrive in tropical conditions — high humidity, moderate moisture and dappled sunlight. Keep the plant shaded in the heat of the afternoon to prevent sunscald on the leaves.
If you have the plant in these conditions and it still fails to bloom, it may be time to repot it with some fresh, high-quality potting soil. If it has been in the same container for three or more years, you may want to consider moving it into a slightly larger pot. Repotting is best done just before active growth in April or early May.
In the meantime, you should begin an in-season fertilization program for your begonia. Use an organic, water-soluble fertilizer (my favorites are liquid kelp and fish hydroslate) every three weeks from March through August. Dilute it with the irrigation water according to label instructions. Do not fertilize with any products containing more nitrogen than phosphorous as this will cause the plant to generate more growth at the expense of flower production.
Another thing you may want to consider is giving your plant a good haircut. Angel wing begonias are quite tolerant of heavy pruning, and doing so will help manage the size and often promotes flowering. You can even root the branches you trim by dipping their ends in rooting hormone and inserting them into a pot of sterile potting mix.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Grow Organic” and “Good Bug, Bad Bug.” Her website is www.jessicawalliser.com.
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