THE genus begonia includes over 2,000 species and hybrids with diversified habitats and appearance. We grow them for their flowers, foliage, or both. Begonias vary in size, from tiny plants to three-metre tall plants with stout stems.
Not that they do not have common features like asymmetrical leaves grown from stipules – the leaf-like sheaths. The flowers are borne in clusters on short stalks arising from the leaf axils.
Male and female flowers are separate on the same plant and each cluster has flowers of one sex only – male flowers tend to be more eye-catching because their petals come in different shapes and sizes. Petals of female flowers are always the same shape and size. The most distinctive feature is the female flower has a three-lobed seed bearing ovary just behind the petals.
The length of floral displays is different – male flowers last only a few days, while the female flower lasts for weeks or even months with the seeds inside.
All begonias are best grown in the shade or with less direct sunlight. Begonias can also perform well as indoor ornamentals.
STRIKING: Begonia flowers can last from just a few days to months depending on the variety and sex.
Groups of begonias
Begonia is named after French botanist and French-Canadian Governor Michel Begon. Because of the huge number of varieties and hybrids, begonias are now grouped based on the different storage organs or root structures of the plants.
Many have fibrous root structures. A second group has roots growing down from a thick creeping rhizome. The third group includes the tuberous species, which has a fleshy, swollen storage organ at the base of the stem as a bulb for regrowth. Others like to group them as tuberous, semperflorens and perennial. I find it easier to distinguish them by root types – tuberous, fibrous or rhizomatous.
Whatever the grouping of these plants, we find the semperflorens are the most common and ever-flowering type. All varieties are compact with dense foliage and only reach 15 inches tall. The colours are the most complicated to recognise – some are red, white, pink or yellow with a mixture in between. This is due to continuous hybridisation, which makes them increasingly difficult to recognise or even distinguish by grouping.
Cultivation choices
The best varieties for us here are shrubs and semperflorens. Shrubs are a vast group with thousands of leaf types and shapes. They are easy to grow using cuttings. You find that local nurseries often sell them during festivals. They are also used for stage decoration or hanging baskets.
Semperflorens are fibrous rooted begonias and they all have round waxy leaves with many flowers – single or double. Some have felt-like white or brown leaves.
FRENCH FLAIR: Begonias are named after French botanist Michel Begon, who was also a French-Canadian Governor.
Planting techniques
Select the variety based on the main purpose. Buying them from a good nursery is better than starting with cuttings. You can use cuttings when you have established plants and wish to propagate additional stock for your garden. Seeds are also an easy step to acquire stock plants.
Use pots that can be hung or placed on stands right from the start. The leaves and stems can be rather brittle and will break if handled for re-potting later.
The best medium is peat moss. Chose a type that has been incorporated with the necessary fertiliser for tender plants, such as organic fertiliser. Be warned that begonias can easily be killed due to over-fertilisation. Liquid fertiliser applied as a foliage spray is good.
The planting mixture can be covered with mulch to maintain adequate moisture. However, you should also ensure that there is good drainage below or else waterlogged containers would definitely kill the plants.
Begonias thrive best in misty or high humidity areas. A mist spray is better than pot watering. Use a hand sprayer, particularly after a hot afternoon.
Pests and diseases
White mealy bugs are the worst pests and very commonly stick themselves on the ventral side of leaves. You can spot this when there is cottony growth along the midrib of the underside of leaves. Remove the affected leaves immediately and follow with a white oil or albolinum spray.
Some caterpillars may take off large portions of the leaves as they come in groups.
Diseases often follow over-watering or a growing medium that is too wet, especially after monsoon rains. Do not expose begonias to harsh weather – prolonged direct sunlight or heavy rain.
Fungal problems like damping off disease and leaf botches can be sprayed with thiram or other types of fungicides. It is easier and cheaper to replant in new soil or peat moss with new materials.
For details send me an email. Happy gardening.