Growing Begonias: Rewarding To Say The Least

gwbgnsLike skirt lengths and heel heights, flowers fall prey to the whims of fashion. A plant that one moment pleases everybody and her mother can scarcely be spotted the next. Take begonias, for instance. Indoors, in the 1960s and ’70s, no college dorm room was complete without at least one rainbow-leaved Rex (Begonia x rex-cultorum) dangling from a macrame hanger. Outdoors, walkways, window boxes, and planters lined with small-leaved wax begonias (B. x semperflorens-cultorum) in vivid reds and pinks stood as living advertisements for the family Begoniaceae.

Then, quite suddenly, these versatile ornamentals entered horticultural obsolescence. Why? Perhaps the begonia’s association with Victorian carpet bedding (now considered by many gardeners to be the apex of bad taste) had something to do with the fall from grace, but unfairly so: The foot-tall hybrids commonly used today for bedding were in fact too large and colorful for the two-dimensional schemes of Victorian landscape designers, whose interest at first lay more in foliage than in flowers. The easygoing disposition and widespread availability of many begonias may have led these useful bloomers into plant purgatory, as well: Where was the challenge in growing something so tolerant of shade, mediocre soil, and neglect that one saw it absolutely everywhere?

A Noble History

While begonias remain among the easiest of plants to propagate and maintain, the number of available forms and cultivars has increased so dramatically in the past quarter century that “common” no longer applies. A new generation of gardeners is discovering the versatility of these tropical natives, whose species number about 1,300, with more discovered and hybridized every year. By contrast, a mere 100 or so species were known in the 17th century, when monk and botanist Charles Plumier named the plants in honor of Michel Begon, governor of Santo Domingo, who had introduced the grateful Plumier to Louis XIV.

In 1865, begonias became major players in the conservatories of the wealthy and powerful when botanist Richard Pearce returned from the Andes, bringing with him the parent of today’s tuberous types. The current undisputed queens of hanging baskets, these showy summer and fall performers include the aptly named Camellia type, with 10-inch single and double blossoms in hues from ivory to cerise. The Carnation, or Fimbriata, type offers fringed blossoms on plants 12 to 18 inches tall. Of similar stature are Picotee begonias, in bicolored blends of apricot and yellow, pink and white, and the reverse of both these combinations. Cascade begonias in soft pastels make ideal candidates for freestanding planters, window boxes, and baskets.

All tuberous begonias flourish in partial shade, provided soil is well drained (overwatered plants are quick to rot) and temperatures do not consistently hover above 90 [degrees] F. Most tolerant of sun are the multifloras, bushy plants about a foot tall that bear flowers somewhat smaller than other forms. Since tuberous begonias are winter hardy only in frost-free zones (9 and 10), gardeners in Zone 8 and north will need to lift their plants before the first frost if tubers are to be saved for subsequent seasons. To preserve tubers, allow them to go dormant by withholding water, then remove all stems and foliage. Store tubers dahlia-style, in sawdust or dry peat, before potting them up again in early March. Nurture the young plants indoors, allowing plenty of time for strong root systems to develop. When all danger of frost is past, gradually acclimate the begonias to outdoor conditions.

Also suitable for outdoor container gardens as well as the front of borders are the aforementioned wax, or semperflorens, begonias. These fibrous-rooted hybrids boast a compact habit with small, fleshy leaves and nonstop flowers in shades from rose to ruby. Contrasting button-shaped centers give the inch-wide blooms a perky appearance. ‘Curly Locks’, for example, bears candy-pink flowers accented by a sulfur-yellow eye. In general, wax begonias require more sun than do their tuberous cousins. Pinching out the tops will encourage bushy growth and larger flowers.

From Garden to Living Room

While many gardeners treat wax begonias as annuals, they are, in fact, tender perennials suited to indoor culture. Plants enjoyed outdoors in summer can be potted up and brought indoors to adorn winter tabletops (specimens are best moved before frost hits, in order to give them plenty of time to adjust to their new surroundings).

Gardeners who would rather bring in their begonias than watch them perish outdoors in the cold also rave about other fibrous-rooted types, including Angel Wing begonias (B. coccinea). Grown for their richly textured, colorful foliage as well as for their flowers, these and other fibrous types are among the easiest begonias to please indoors, notes Byron Martin, third-generation nurseryman and president of Logee’s Greenhouses, in Danielson, Conn. “Flowers are just a small part of the story – the richness of the foliage is simply not matched by any other plant.” Sited in a west-facing bed protected from strong afternoon sun, disease-resistant hybrids boast mottled, dotted, and otherwise variegated leaves in a variety of textures and shapes that can be used to design a garden of extraordinary depth and diversity. When potting up plants for their winter hiatus, Mr. Martin advises topping off the plant to about six to 10 inches from the soil level. He also suggests pruning roots so that the begonia fits comfortably and securely in its new container.

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