Most bulbs are acquired and planted when dry, in a dormant, leafless, rootless state. Plant as soon as possible. They may flower poorly following later than recommended planting or after lengthy storage (see Problem section for more detail).
Planting in borders
Aim to plant in groups of at least six, as the more bulbs that are grouped together, the better the display. Typically, 25 to 50 bulbs may be needed to make an impressive show.
This method applies to spring-, summer- and autumn-flowering bulbs:
- Dig a hole wide and deep enough for your bulbs. Work out the planting depth by roughly measuring the bulb from base to tip and doubling or tripling this length – this figure is the rough planting depth. For example, a 5cm (2in) high bulb should be 10-15cm (4-6in) below soil level
- Place the bulbs in the hole with their ‘nose’, or shoot, facing upwards. Space them at least twice the bulb’s own width apart
- Replace the soil and gently firm with the back of a rake. Avoid treading on the soil as this can damage the bulbs
Some bulbs, such as winter aconites, bluebells and snowdrops, are thought to be best planted, moved or divided ‘in the green’, when flowering is over but they are still in leaf. However, dried bulbs are often offered and can be successful.
Most bulbs are ideal for growing in containers, but this especially suits those with large, showy flowers, such as tulips, lilies, arum lilies and alliums. Here are some tips for success:
- For bulbs that are only going to spend one season in their container, use a mix of three parts multi-purpose compost with one part grit. For long-term container displays, use three parts John Innes No 2 compost mixed with one part grit
- Plant at three times their depth and one bulb width apart
- Water bulbs regularly when in active growth, but you can reduce watering once the leaves start to die down and then through the dormant season. However, continue to check pots in winter, ensuring they do not dry out completely
- To promote good flowering next year, feed the bulbs every seven to ten days with a high-potassium fertiliser such as a liquid tomato feed. Begin feeding as soon as shoots appear, and stop feeding once the foliage starts to die down at the end of the season
- If you bring pots of hardy bulbs indoors during flowering, put them in a sheltered spot outside as soon as flowering is over