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 19th
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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.