Uses | Plant raising | Planting | Aftercare for bulbs
Included here are bulbous plants with corms such as gladiolis, tubers such as begonias, rhizomes such as cannas and true bulbs – all types of storage organ. Plants in this group find many uses. Bulbs are ideal for use with spring and summer bedding plants, and they are lovely in pots with spring bedding plants, or on their own. They can also be used to bring colour to herbaceous and mixed borders in spring, summer and autumn. Certain bulbs can be used in semi-wild conditions – ‘naturalised' under trees or shrubs, in grass or ground cover.
Bulbs are usually raised as offsets from the mother bulb, and will, in three or four years, grow to flowering size. Many types can be grown from seed too, taking about the same length of time to flower.
Bulbs need well drained, fairly rich soil, particularly tulips and gladiolus. Plenty of organic material is important to open the soil and allow air to reach the bulbs. Water-logging rots most kinds of bulbs, so avoid damp spots, except for a few that like damp ground, such as cammasia, snakeshead fritillary and leucojum.
Plant the spring-flowering types in October and the summer and autumn-flowering types, such as dahlias and gladiolus in spring/early summer. As a general rule, plant bulbs at a depth equal to twice their height. This helps to support the stems.
For naturalising, plant the bulbs at random, but not too far apart. Simply lift the sod and pop the bulbs in. Bulbs in pots or bowls can be potted up in early September for flowering at Christmas. These should be kept in a cool, dark place indoors, or buried outdoors – bowl and all – until early November when they are brought into a warm room to flower.
Tender bulbs such as dahlias, gladiolus and begonias, lifted and stored from year to year, can be started into growth in March in a greenhouse or a warm sunny window sill in trays or pots of moist compost. Alternatively, plant them out to their flowering positions, unsprouted, in late April.
Aftercare for bulbs
Bulbs generally need little attention but keep them reasonably weed-free for best results. Some fertiliser, every few years, helps to maintain flowering. Frost-prone plants, such as dahlia, begonia and gladiolus, will have to be lifted in autumn and stored indoors for the winter. They might be risked outdoors by covering them with a layer of peat or ashes.
Bulbs naturalised in grass must not have their foliage mown off until it goes yellow and begins to die. This is usually in late June and a lawn may look very ragged by then. It is best to naturalise bulbs in lawn areas that would not be conspicuously untidy if left unmown, such as under trees. Otherwise, naturalise the bulbs in ground cover, such as ivy, ajuga, or acaena.