Planting techniques for bulbs, in the ground or in containers`
When to plant bulbsWhere to plant bulbsHow to plant bulbsProblems Suitable for… Bulbs are useful for adding colour to spring borders. Tulips come in all shades, from dark purple to white, and bloom at a time of year when many plants offer muted colours. Other bulbs, such as snowdrops and scillas, are some of the earliest flowering plants in the garden, brightening up the short days of very early spring.
Planting summer-flowering bulbs such as lilies and gladioli can provide dramatic, tall blooms that are scented.
Autumn-flowering bulbs, such as nerines, can brighten up the late season with unexpectedly colourful displays.
When to plant bulbs Autumn Plant spring-flowering bulbs, such as daffodils, crocus and hyacinths, preferably by the end of September Plant tulips in November Plant hardy summer-flowering bulbs, such as lilies, alliums and crocosmia, in September and October Spring Plant tender summer-flowering bulbs, including gladioli, in early spring Summer Plant autumn-flowering bulbs, such as nerines, by late summer Where to plant bulbs Some bulbs need specific siting;
Most hardy bulbs, including tulips and daffodils, prefer a warm, sunny site with good drainage as they come from areas with dry summer climates Bulbs from cool, moist, woodland habitats, such as Cardiocrinum, need similar garden conditions. Improve light or sandy soils with garden compost and heavy soils with compost plus grit How to plant bulbs 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. Plant most bulbs at two to three times their depth. For example, for a bulb measuring 5cm (2in) high, dig a hole 10-15cm (4-6in) deep and sit the bulb in the bottom of it 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 If the ground is moist or the bulbs are autumn-planted, watering is not critical. Otherwise water straight after planting 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.
In containers 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 once after planting then 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