Introduction: Begonias are mostly succulent
herbs from the tropics. Although tropical in origin, begonias are usually found in
partially shaded, moist and humid locations, often at higher elevation. Most can not
tolerate high temperature, but grow best at moderate temperatures. Begonias are
monoecious dicots, producing both male and female flowers on the same plant. The
female flowers are noticeable for the three winged ovary at the base of the petals
whereas the male flowers usually have only two petals. Seeds are very small.
There are over 1,000 species, mostly in the genus Begonia and 10,000 cultivated
begonias. The major groups include the fibrous-rooted, rhizomatous and
tuberous-rooted begonias. Many begonias are grown as outdoor ornamentals, but
most are indoor plants and those commonly grown outdoors generally make attractive indoor
Wax begonias, Begonia
semperflorens, are very popular fibrous rooted begonias. They have waxy leaves
and flower freely. Leaves may be green, bronze or red and flowers may be single or
double in shades of red, pink, orange and white. Wax begonias often do best in
moderate to bright light in winter and partial shade in summer. Many cultivars grown
in cooler parts of the temperate zone thrive in bright light at cooler temperatures but
new groups of cultivars have been developed for use in warmer climates and these grow well
at higher temperatures and can tolerate higher light intensities at those temperatures
Angel wing begonias have long, cane-like stems and leaves shaped like the
wings of an angel. Both standard and dwarf forms exist and many variegated and
on-variegated leaf patterns and flower colors occur. Flowers are usually produced in
large, pendulous clusters.
The beef steak begonia is an example of a rhizomatous begonia. It has a
heavy, succulent stem that grows just above the soil surface and sends out adventitious
roots. These begonias send flower stalks of many small flowers well above the
foliage. Many different leaf color patterns occur, the leaves have various shapes,
leaf margins range from entire to deeply lobed and many have hairy leaves.
Rex begnoias are mostly rhizomatous begonias. Their main feature is
foliage with many bright and unusual color patterns. Their flowers are usually on
very small stems and hidden be the leaves. This group of begonias will grow in
filtered light or indirect light and may burn if they are in direct light.
Tuberous-rooted begonias are
especially common in cooler parts of the temperate zone. They produce large showy
flowers on small upright or cascading plants. Most require special care when grown
in warmer areas. Tuberous-rooted begonias often have a summer or winter rest
General Care of Begonias:
||Moderate temperature is best. Some begonias
prefer cool temperature. Most are forest floor plants but some have origin or adaptation
to high elevation in the tropics, hence their preference for cool to moderate temperature.
||Media rich in organic matter are best for most
begonias. The potting medium could be peat or compost or a mixture of peat or
compost with sand or other ingredients.
||Begonias should be kept moist and for many the
medium should be allowed to dry between waterings. Although some will tolerate
having wet soil, most do not. Avoid water with high salt content, especially sodium,
as this will burn the plants and damage the very fine roots.
||Moderate light is best for most begonias though
many tolerate low light. Bright light would damage most begonias, though it does not
burn many cultivars of wax begonia.
||The aroids respond to fertilizer. Large
leaves are the result of ample fertilizer. A fertilizer higher in nitrogen than
phosphorus and potassium is common. The roots of begonias are especially sensitive to
salts. Careful application of inorganic fertilizer is essential. Most thrive
with fertilizers containing a little more nitrogen than phosphorus or potassium, but those
grown for heavy displays of flowers need a fertilizer with adequate amounts of nitrogen,
phosphorus and potassium. Since begonias are grown in media high in organic matter,
their nutrients can be derived from organic matter.
||Most begonias thrive at higher humidity, producing
larger leaves and less marginal burning of the leaves.
|pests and problems:
||Begonias are relatively pest free, though pests
such as mealy bugs may become numerous and should be treated.
||Keep yellowing and dead leaves trimmed off.
Make cuttings of long stemmed types to reduce their legginess. Remove spent flowers.
||Seed and stem cuttings are very common, and leaf
and leaf section cuttings are also used.