Begonias

Begonias belong to a diverse family of over 2475 different species and cultivars. The Ancient Chinese appreciated their beauty but Begonias were not introduced into Europe in any great quantity until the 19^th Century. This late introduction and their dislike of frost means they are not found in the English ‘Cottage Gardens’. There are two common methods of propagation: rhizomes and leaf-cuttings.

• Rhizomes: -Rhizomatous begonias can be grown from small sections of the rhizome. Use clean secateurs and cut a 1-inch (2.5-cm) piece from the growing tip or further down. Remove the large leaves and put in potting mix to half its depth (1-cm) with the root facing down. Best done in Spring or in temperatures above 20 degrees. Roots develop in a month and can then be potted up.

• Tip Cuttings: -Remove the flowers and all leaves except for the top. Pot as for other cuttings.

• Begonias can also be propagated from seed and leaf-cuttings.

Growing

It is essential to plant Begonias in well-drained soil as water‑logged roots die. Never allow them to stand in water. To maintain humidity, stand the pot on a saucer filled with pebbles and keep the water level below the top of the pebbles. Begonias are voracious feeders. During growing season, feed once a week with a liquid fertiliser (hang a calendar in your shed), or use slow-release Ozmacote Plus, or blood and bone (plus minerals).

Begonias are grown for foliage, their flower and form. The flowers are not good in floral art, but massed plantings can be spectacular with a wide variety of colour, shape and size in leaf, flower and also ‘canes’.

History

Begonias originated in the tropic and sub-tropic regions (South and Central America, South Africa, South East Asia, Indonesia and Papua New Guinea). One species is from Hawaii, but there are none from Australia. There are 8 or 9 general types of Begonia, of which the following 6 are most common.

1. Rhizomatous Begonias – originate from Mexico. Spring flowering and many look great in baskets. Will grow under trees and in shady areas (with darkened leaves). Lighter-leafed varieties take sun. Flowers carried for weeks. Good varieties include heracleifolia, ‘Cathedral Window’; for silver leaf ‘Silver Tiara’ (pink flowers), ‘Silver Jewel’ (white flowers), ‘Silver Misono’ for hanging baskets, indoor pots or shady gardens; Beefsteak (Erythrophylla) for mass-plantings; ‘Manicata’ for variegated leaf in afternoon sun. ‘Oyster Leaf’ grows from upright rhizome. Don’t hesitate to tip-prune as these grow to large plants. Grow several together as they do better than in single plantings.

2. Bedding Begonias – Semperflorens Begonias (known as ‘Semps’) are wonderful in mass-plantings or used as borders (double or triple rows). Take full sun or full shade. Plant 8 to 10 in a pot and prune back to roots when too tall and then feed. Will grow from seed, or basal and tip cuttings. Basal is better. Divide large individual plants. Semps feature in the Fitzroy and Ballarat Gardens in Victoria.

3. Cane Begonias – ‘tree’ or ‘angel wing’ Begonias are best outdoors in frost-free gardens. Can be grown in large pots in a protected area. Prefers a high-level of morning sun. Deep-rooted plants, new canes grow from the root system on the outside of existing canes. Prune back to 12-inches (30cm) high in late Winter. Varieties include ‘Zulu’(‘Lenore Oliver’) with red flowers and black leaves, and ‘White Shower’ white leafed with a choice of flower colour – red, pink and white. Recommend that these are chosen and bought in flower.

4. Shrub-like Begonias – second largest group after Rhizomatous (300 species and cultivars). Ideal garden plants, great in hanging baskets and happy in pots. Great variation in leaf shape, size and growth habit. B listada is sprawling; B cubensis is compact and medium-height; B fuchsiodes and B scharffii are tall, useful in cut-flower arrangements and last a long time in water. B acutifolia from Jamaica (discovered in 1688), flowers year-round, with pink flowers in full-sun that are almost white in full-shade. ‘Little Brother Montogmery’ is for foliage and baskets. ‘Richmodensis Purpurea’ is small-leafed in pot or garden, flowers 9 months of year in shade and responds well to tip-pruning.

5. Trailing/scandent Begonias – ideal in baskets, but needs watering. Plant two together, tip-prune to encourage branching and grow on trellis. B convolvulaceae needs to be tied or intertwined through the support, and has masses of tiny white flowers.

6. Tuberous Begonias – do NOT need a glasshouse but do need protection from strong winds and direct sunlight. Rain damages the flowers. These are winter-dormant and so must be lifters and replanted in September. Go to Ballarat’s walk-in glasshouse for a wonderful display. Melbourne’s Fitzroy Gardens also have a display of hanging baskets. The Tuberous begonia is Belgium’s ‘national flower’, so there are spectacular displays of over 80,000 plants each year in Brussels’ public square.

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