Some of our favourite garden plants are bulbs, including daffodils, tulips, snowdrops, crocus, lilies and gladioli. Planted while they are dormant, it usually takes just a few months for them to grow and bloom. They really are the buried treasure of the garden.
The cultivation techniques used to grow bulbs are quite simple but, because they can be grown in containers, borders and also naturalised in grass or under trees, there are several methods for planting. They are popular for indoor flowers at Christmas.
Watering and feeding
All bulbs need adequate water while in growth, and for six weeks after flowering. Check pots to make sure they don’t dry out during the growing period. The compost should feel moist but not wet to the touch.
Apply a general-purpose fertiliser, such as Growmore (35g per square metre/1 oz per square yard), to borders in late February to encourage bulbs to flower well in the following season. In containers, use a liquid high-potassium feed, such as tomato fertiliser, from early spring until six weeks after flowering.
Cut back spent flowers to the base of the flower stalk if seed is not required for propagation. This will prevent the plant spending energy on seed production, conserving resources in the bulb for next year’s display.
Cutting back bulb foliage
Wait for a minimum of six weeks after the end of flowering before cutting back the dead foliage, and ideally only remove foliage when it is yellow and straw-like. Until this time, the bulbs should be watered and fed as above. Also, do not tie or knot the leaves.
Lifting and storing bulbs
Only lift and store bulbs where this is practical. Those naturalised in areas of grass, or planted in borders or containers where they are underneath and coming up through shrubs or perennials may be left in the garden during the dormant season.
Once the foliage has died down, carefully lift and clean the bulbs. Trim back roots and the outer layers of loose, flaking tunic.
Only healthy bulbs of a good size should be kept. Damaged or diseased bulbs must be discarded. Lay bulbs on a tray to dry for 24 hours to help prevent fungal rots developing in storage.
Put the bulbs in labelled paper bags or nets and store in a dry, cool place.
Apart from a few problems, bulbs are relatively trouble free. Just discard damaged or diseased bulbs before storing, and do the same with those that have yellow mottled foliage as this usually indicates an incurable virus infection. Some bulbs can become invasive, and spring is a good time those that have spread too far.
Other problems that can affect bulbs include aphids, slugs, snails, narcissus basal rot, narcissus bulb fly, tulip fire, and tulip viruses.