Tuberous Begonias
Although there are many different kinds of begonia, including some which are grown only for the beauty of their leaves, the- kinds most people grow are those which are grown from tubers.
These are known as tuberous begonias. There are several different kinds of these. Perhaps the most popular are the large double-flowered hybrids used for summer decoration in greenhouses, window-boxes, tubs and other containers and for summer bedding. These have flowers like large roses, although some of them are described as being like camellias or carnations. Some have frilled edges to their petals . These are dwarfish in growth and are use- ful for bedding. Others have a thin line of another color round the edges of their petals (picotee types).
There is a good range of colours including all sorts of pinks, scarlets and crimsons, oranges, pale and deep yellows, some fine white varieties and a few bicolours.
Types of Tuberous Begonias
Two more kinds of tuberous begonias are worth growing. The dwarf types often seen in summer bedding schemes in public parks and private gardens are called multiflora begonias. Their flowers are small compared with the large-flowered hybrids, but they make up for this by flowering very freely from early summer to late autumn with very little attention. Several varieties are available in pinks, reds and yellows.
The other tuberous kinds are the ‘pendula’ begonias much used in hanging baskets and sometimes called ‘basket begonias’. Their growths are drooping and they flower so freely that a well-planted basket appears to be covered with bloom. About ten or a dozen varieties are on the market at present in yellows, scarlets, pinks and oranges.
Starting Begonias From Tubers
March is the time to start work with these tuberous begonias in the warm greenhouse. If you have no greenhouse the tubers may be started in a warm light room. The equipment you will need to start is simple, merely some 4 inches deep seed trays and a sufficient supply of peat and sharp sand or old potting soil.
Put a layer of rough leal-mould, lumps of peat or broken flower pots in the boxes first.
Then fill them with the rooting material and place the dormant tubers in this about 2 inches apart. They should be almost but not quite covered. It is easy to see which way up they should go as the remains of old roots are visible on the bases of the tubers. The rooting material should be moist to start with, but not wet, and only light sprayings should be needed after this until growth starts when more water will be needed. If you cover the boxes with sheets of glass and keep them shaded, less water will be needed, but the glass must be re- moved when leaves develop.
Potting and Growing On
When the young leaves are about 2 inches or so tall lift the tubers carefully to avoid damaging the roots and pot them up. Use small pots containing a well-drained compost of 7 parts loam, 3 parts peat and 2 parts sand (or John Innes Potting Compost) and pot the young plants on again into 5-inch pots when they begin to fill the first pots with roots. The final potting should be into 7-inch or 8-inch pots. Two or three weeks after this. Feeding with dilute liquid feeds may be started, but this should not be overdone.
Outdoor and Greenhouse Care
Begonias may be planted outdoors in late May orearlyjunc. In the greenhouse. During the summer, plants like plenty of fresh air and shade from strong sunshine and indoors and out they benefit from an overhead spray with water in the evenings.
