Culture

The following is a general guide for the common begonia groups; if you are seeking more detailed information or description, please contact the Society.

Cane-like

These have erect or semi-erect smooth bamboo-like stems which are not branched, or branch rarely; they are nearly all suitable for the garden. Many produce large, spectacular flower clusters over a very long flowering period. As with all begonias, the soil or potting mix needs to be free draining, raising the garden bed if necessary. Grow in good light, hardy kinds will flourish and bloom exceptionally well in sheltered gardens with morning sun; be careful with hot afternoon sun.

Canes need to be fed regularly during the growing season with a slow release fertilizer and an occasional liquid seaweed feed. Annual pruning in early spring is beneficial, old brown non productive canes can be removed completely at the base, others can be reduced by about 50% and newer canes allowed to develop untouched.

Cane begonias are very easy to propagate from tip cuttings.

Shrub-like

As the name implies, begonias in this group are bushy in growth habit. They branch freely, produce new shoots at the base and can be pinched back to form good specimen plants and are excellent for the garden. The leaves of this group are very variable in size, shape, colour and texture; some grow in sunlight, others in shade. Some are small and neat others tall and leggy, some are almost ever blooming, others flowering just once a year. They are much fuller growing than canes and are attractive all year round because of their more varied and interesting leaf types; there are shrub-like begonias suitable for every situation; fertilise as for canes. Prune to shape after flowering and propagate from stem cuttings or seed.

Rhizomatous

This is the largest begonia group with hundreds of species and thousands of hybrids. Most have rhizomes which run along the surface of the ground whilst others are erect or underground. Most are grown for their interesting leaves and compact growth but they have the added bonus of a massive display of flowers, usually winter/spring. Although some rhizomatous begonias will grow well in the garden, they are shown to best advantage when grown in pots and mature plants make spectacular hanging basket subjects.   Do not overwater rhizomes, they will do well through winter with very sparse watering and are happy in the same pot for some years. Propagate from rhizome or leaf cuttings or leaf wedges.

Trailing-Scandent

A small group of begonias for the hanging basket enthusiast, they either trail or climb depending on how the grower wants them to behave.  Most branch readily and produce many basal shoots so that mature plants are very full. Trial and error will as usual determine the best location for hanging baskets but perhaps best grown in a bush house or hanging under a tree in filtered sunlight.  Systematic pinching and pruning will help produce a full and attractive plant with old stems being pruned back hard.

Rex Begonias

These beautiful plants are in fact rhizomatous begonias but are classified separately because of their distinctive ornamental foliage and are best grown indoors or in bush houses. Successful rex cultivation depends on the use of good free draining potting mix and attention to the environmental factors of:

Keep on the dry side in winter. Rex begonias are susceptible to mildew and preventative measures are advised; give the plants plenty of space for good aeration, provide good ventilation and keep moisture away from the leaves.

Tuberous Begonias

These are the begonias with spectacular flowers which many garden lovers know from the annual displays at Ballarat, Orange, Bathurst and Goulburn and are most suitable for pot culture in shade or glass houses.  Tuberous begonias grow to perfection in areas with cool day temperatures and cool nights, but seem to adapt successfully to conditions both in the Lower Blue Mountains and in the Western Suburbs of Sydney.

For more detailed information, please contact the Society.
Peter Sharp's book 'Down to Earth - With Begonias' can be viewed on the linked 'The International Database of the Begoniaceae' and is highly recommended reading.