Planting summer bulbs

What to do

Select bulbs

• Buy dry bulbs when they're as fresh as possible. Summer bulbs are usually on sale from early spring onwards, when they're dormant.
• Healthy bulbs will feel firm and show no signs of mould or damage. Look for bigger bulbs as they'll produce bigger blooms.

When to plant

• Summer bulbs, such as alliums, agapanthus and cannas, should be planted in spring, when the soil is beginning to warm up.
• The ideal soil temperature is 13°C as in colder soil bulbs will not start to grow and may rot. Aim to plant dry bulbs directly after purchase.
• Bulbs you have stored over winter should be planted at the end of their dormant season.

Soil type

• Different bulbs need different soil types but summer bulbs generally like a warm, sunny position. Free-draining soil is important as bulbs are susceptible to rotting.
• If you have heavy, clay soil dig in one to two buckets of coarse sand per square metre.
• Adding well-rotted organic matter will also improve drainage.

How to plant

• Dig individual holes for each bulb or a trench for many bulbs. Place bulbs in the holes without pushing down hard.
• Make sure the growing point is pointing upwards. Cover with soil and firm.
• Pot-grown bulbs may be planted directly in their desired position in a border where you want them to flower. This is known as planting 'in the green'.
• For these plants make a hole wide and deep enough to allow room for the roots to spread and plant the bulb at the same depth as before.
• Many summer bulbs are ideal for growing in patio containers, especially tender species. These can then be lifted in winter and stored.

Planting depth and spacing

• Use the bulb as a guide and plant it two or three times its depth. Space them approximately two to three bulb widths apart.

Lifting and storing

• Most summer bulbs are not hardy so need to be lifted before the first frost. Bulbs generally prefer to be stored dry.
• Remove loose soil, carefully pull or cut off dead and dying leaves and leave to dry overnight. Dusting with fungicide will help keep the bulbs healthy.
• Store the bulbs in dry paper bags or trays of almost dry sand in a frost-free place.
• A few bulbs need moist conditions and can be kept in slightly damp bark chippings.

Watch video

In this video Carol Klein plants exotic bulbs (Peacock flowers) and tubers (Begonias) in early April for late summer colour.

Bulbs to try

• Allium christophii - huge, globe-shaped, purple flower-heads
• Agapanthus 'Castle of May' - tall South African plants with deep blue, showy flowers
• Canna indica - lush green foliage and bright red flowers
• Lilium 'Arena' - impressive, scented, white flowers, with yellow and deep orange stripes
• Nectaroscordum siculum - large, nodding clusters of pink-cream flowers