Begonia tubers are tender and should not be planted until the frosts have passed. You can always start the tubers off indoors in pots. Follow the planting instructions above and keep in a warm, brightly lit spot.
When the weather has warmed up, harden off the plants by moving them outside during the day and bringing them back in at night for a week or so. Then plant the tubers outside.
Feed the plants every two weeks with high-potassium fertiliser like tomato feed. Water well during dry weather but try not to soak the leaves.
How to lift and store summer bulbs
Many summer bulbs, including dahlias, gladioli and begonias, are damaged by frost and should be stored indoors over winter.
Wait until all the leaves have died down at the end of summer. Lift the bulbs out of the soil with a garden fork, taking care not to damage them.
Remove any dead or dying leaves and cut back the leaves or stems to within one inch of the bulb. Leave the bulbs out in the sun to dry out. Then brush all the soil off them.
Store the bulbs in mesh bags in the shed or garage. They need air circulation to stop rot setting in. Keep checking the bulbs and remove any that start to rot. Replant them again in spring.
See my full collection of summer-flowering plants for John Lewis.