Summer bulbs are ideal for patio containers and add colour to mixed borders without taking up too much space.
Most summer flowering bulbs are tender and are planted in late spring after the last frost of the year. In frost prone areas most of these bulbs must be dug up in the autumn and stored indoors over the winter. The bulbs are lifted before the first frost, remove loose soil and cut off dead and dying leaves before storing them in a frost free place. Some of these bulbs can survive the winter outdoors. Summer flowering bulbs include dahlias, begonias, crocosmia, lilies, gladioli, agapanthus, tigridia, nectaroscordum, cannas, and alliums.
Buy dry bulbs when they are as fresh as possible. Summer bulbs are usually sold from early spring onwards, when they are dormant. Healthy bulbs will feel firm and show no signs of mould or damage. Plant dry bulbs directly after purchase. The bulbs generally like a warm, sunny position in free-draining soil to prevent them from rotting. If you have heavy, clay soil dig in one or two buckets of course grit. Mixing well-rotted compost or manure will also improve drainage.
Bulbs must be planted deep enough. A planting depth equal to twice the height of the bulb is a good rule of thumb. Space bulbs at two to three times their width. Plant the bulbs with the pointed end upwards. Cover the bulbs with soil and apply a layer of mulch to protect against frost and stop the soil drying out. Plant bulbs in groups, either in small clusters or large beds, a single flower standing on its own is not very dramatic. Plant low-growing bulbs in front of taller varieties. Summer bulbs can be bought growing in pots from garden centres.
After the flowers have faded cut off the dead flower heads to stop them going to seed and allow the green foliage to die back naturally. During this period the leaves need sun to produce food to recharge the bulb for next year’s blooms. If the dying foliage seems unattractive the best solution is to camouflage the foliage with hostas or other leafy perennials. Apply a potash-rich liquid fertiliser, like tomato feed, to the bulbs after the flowers have faded – this will feed the bulb for the following years.
Jobs for the week
This is a busy time in the garden, the weather has been improving and the evenings are getting longer. Now is the time to tidy up the herbaceous bed, remove all the old stems of last year’s flowers. Remove all weeds and apply a mulch of compost.