Growing Bulbs andTubers: Dahlia Summer-Flowering Plants
These are among the most showy of summer-flowering plants. Unfortunately, they are only half hardy and tubers cannot be planted out of doors until April. It is possible to start them earlier under glass and they can be planted out of doors as soon as there is no risk of severe frosts. After flowering the tubers should be lifted in the autumn and stored in a dry frostproof place until planting the following spring.
Dahlias revel in rich soil and for preference the site should be prepared in the autumn, working in plenty of decayed manure and bonemeal. If the job cannot be done then, work the soil deeply in early spring. Sometimes the tubers are supplied in polythebe bags and these may be safely kept until planting time if stored in a frostproof place.
The planting procedure is simple. Plant each tuber 6 in. deep with the growing tip upwards. Allow 3 ft. between the taller varieties and 2-1/2 ft. between the less tall ones. Drive a tall, stout stake into place before you cover the roots.
Start tying the stems to thewhen they are about 2 ft. tall. To obtain the finest flowers, the buds should be restricted to one per stem, the end bud being retained and the side buds removed. Dahlias are greedy plants and should have at least one good feed of a which is low in nitrogen in late July or early August. Use a handful to each plant, making sure not to touch the leaves, and hoe it into the soil carefully. Keep them free from weeds and water frequently. In a hot summer, the plants with or compost.
Dahlias should always be given sunny positions—they flower less well in shade. The various types of dahlias are excellent for beds and borders and for cutting. The dwarf bedding varieties can be most effective in window-boxes or in tubs or urns on the terrace or roof garden. Dahlias are divided into clearly defined sections ranging in height from 6 or 7 ft. down to 10 in. These sections also vary in shape, size, and colour of flower. There is a very wide choice of varieties in all the groups.