The Begonia Show-Offs

Seemingly infinite variety characterizes the genus Begonia. Plants can be long-stemmed or low-growing, have fuzzy or shiny leaves, and produce large flowers or ones so insignificant as to be almost invisible. Probably the most prized though not the most widely grown are tuberous begonias, whose name belies their fulsome displays of mid- to late-summer bloom. The flowers often resemble roses or carnations, and they rarely disappoint growers.

“In my garden I always have begonias,” says Steven Frowine, respected consultant to the horticulture industry. “But I have to be selective in what I grow for my own pleasure. They come in strong primary colors and great pastels, and they bloom constantly, from summer until frost. I don’t know of anything else with the same combination of flower size and shape that blooms in the shade.”

Over the years, breeders have developed strains of tuberous begonias (B. tuberhybrida) that feature ruffled double flowers and “rose form” blooms, and some types have flowers that look like carnations or double camellias. Colors range from white through yellow, orange, apricot, pink, and red. Some have bicolor petals, such as white with a pink edge or yellow with a red edge. Begonias with petals that are edged in lighter or darker colors are called picotee.

What to Look for When You Buy

Buy dormant tubers in winter, either by mail from a specialty nursery or from a nursery or garden center. Another possibility is to buy blooming plants in summer. (By the way, tuber size does not predict plant or flower size.)

Most gardeners buy dormant tubers, which are easier to grow than seed and less expensive than blooming plants. Tubers are also usually easier to find than blooming plants. Although it’s possible to find tubers in nurseries in regions where they grow successfully, the best selection is from specialty dealers. Most of their plants have been grown from seed strains carefully bred for high-quality flowers.

Certain dealers also sell named varieties grown from stem cuttings, such as ‘Avalanche’, ‘Bonfire’ and ‘Falstaff’. These are considerably more expensive (ranging from $8 to as much as $75 each) because the supply is limited and cutting-grown tubers take longer to reach an appropriate size for sale.

Blackmore & Langdon, England’s foremost begonia dealer, is perhaps the world’s best-known grower of cutting-grown tubers. In this country, these tubers are available from White Flower Farm. And last year the well-known Antonelli Brothers Begonia Gardens in Santa Cruz, California, began selling its own collection of cutting-grown tubers.

Many gardeners shy away from tuberous begonias because of their reputation for being difficult to grow. They really aren’t. Although travelers discovered the ancestors of these beauties in the Andes Mountains in the mid-nineteenth century, more than half of the United States has microclimates or growing conditions that can sustain tuberous begonias.

Pests: Mealybugs

Mealybugs rarely reach more than 1/16″ long, but because they feed in clusters they’re easy to spot.

Several species of mealybugs pose problems for gardeners across North America. Host plants include citrus, apples, peaches, grapes, potatoes, and a number of tropical plants — including houseplants. These tiny insects appear in clusters on the undersides of leaves and clumped in the forks of twigs and branches where they suck plant juices. As they feed, some species inject toxins that damage plant tissues.

Mealybugs are oval in shape, with a grainy, dusty looking surface that is actually a protective waxy coating. Large clumps of mealybugs may resemble fur or lint attached to a plant. Symptoms of their presence include yellowing leaves and dark, dirty patches on leaves, which is actually sooty mold growing on the sweet mealybug excretion called honeydew.

In regions without freezing winters, mealybugs are present year round. In colder climates, there may be 2 to 3 generations per year. The pests overwinter as eggs in cottony egg sacs or as tiny nymphs (the juvenile stage, commonly called crawlers).


Controls include insecticidal soap and horticultural oil. Natural enemies include the mealybug destroyer (a kind of ladybug), lacewings, and mealybug parasite (a tiny wasp).

When to Plant Vegetables

By keeping one eye on the signals nature is sending, you can plant your vegetable garden according to nature’s calendar.

If you live in the North were crocus are common, you can time your seed sowing to their their bloom: When you see the flowers, plant the following as seeds outside in your garden: broccoli, Brussels sprouts, cabbage, garlic, kale, kohlrabi, onion sets and seeds, peas, potatoes, radish, rutabaga, shallots, spinach, and turnip. Of course these signals don’t work if you live where frosts in winter are rare or light, such as in much of coastal California, Phoenix, and along the Gulf Coast and south Florida. In those regions, plant these cool-loving crops in October.

These early plants may be ready to go in while your garden is still cold and wet, before the soil is ready to be worked. One way to tell is to step onto the bare garden soil. If your footprint looks wet and shiny, wait. Another way to test is to squeeze a handful of soil into a ball and set it on ground. Poke it with your finger. If it crumbles, it’s okay to plant. If it clings together in a hard ball, wait.

When tulips, daffodils, and maple trees blossom, you can plant beets and Swiss chard by seed. They can take a light frost or two, but not as much as the crops listed above.

When apple trees, lilacs, and late tulips are in bloom, you can plant the following seeds: bush beans, sweet corn, pumpkin, and squash. These crops like summer heat, but can germinate and grow in relatively cool soils.

When the tall, bearded iris bloom and apple blossoms have fallen and summer has arrived, plant seeds outdoors for pole beans, lima beans, cantaloupes, cucumbers, eggplants, peppers, and tomatoes. These are the true heat lovers.