Dos, don'ts and tips for planting bulbs

Spring-flowering bulbs can provide a lively splash of colour to your garden after winter fades. To help you get the best results from your bulbs, here are some important dos, don't and tips.

Do plant in well-drained soil
If your garden soil is clay and drains poorly, add a good helping of sand, compost and even a few handsful of gravel at the bottom of the planting holes.

Do add a bulb fertilizer
At the very least add a balanced, timed-release or organic fertilizer to the soil beneath the bulb at planting time. Fertilize established bulbs yearly, when they are in their most active season of growth.

Do form tight clusters of a single variety
The best place is in a flower bed,  a patch of ground cover, or in a corner of your lawn.

Don't buy bulbs then store them in poor conditions
Poor storage conditions such as too much light, moisture, cold or heat will damage the bulbs. Once they begin to rot there is no point planting them.

Don't plant mixed bulbs that won't flower on the same date
The dramatic effect of massed blooms will be lost and maintenance will be a headache.

Don't pull off or cut the foliage back after the petals fall
Bulbs need to rebuild their food reserves for the following season and their leaves are the means by which sunlight is transformed into plant food. Don't remove or trim back leaves until after they have naturally turned yellow.

1. Chill bulbs
Spring-flowering bulbs begin developing a root system in the fall, and this process may continue all winter.

• Roots develop best when the bulbs are cold, which also keeps them from sprouting too soon.
• When it's said that tulips need 12 weeks of chilling, it means that they need 12 weeks of growing roots in cold soil below 4°C before warm temperatures trigger them to grow leaves and flowers.

2. Plant bulbs tightly
When you plant a bulb, make sure it doesn't remain suspended between the sides of the planting hole with an air pocket underneath.

• The bottom of the bulb needs to be in firm contact with the soil to root properly.

3. Know how deep to plant them
A bulb should usually be buried at a depth at least twice its height.

• Little spring-flowering crocuses should be planted only five centimetres deep, while big tulips may need 20-centimetre deep planting holes.

4. Crate bulbs to move them fast
After the flowers are gone, bulbs need to spend some time storing up energy for next year and they can't do it without their leaves.

• If you are in a rush to replant the space occupied by spring-flowering bulbs, plan ahead by planting the bulbs in wooden or plastic fruit crates buried at the proper depth.
• As soon as the leaves begin to yellow, you can lift them from the ground, crate and all. Then move the crated bulbs, along with their soil, to another area of the garden until they die back completely.

5. Weed bulbs by hand
A cultivator or other sharp-pointed tool can easily damage shallowly planted bulbs and their roots.

6. Don't forget about fall-blooming bulbs
Fall-blooming bulbs include hardy cyclamens, autumn crocuses (Colchicum) and Amaryllis belladonna, with massive trumpet-shaped flowers of pink or white.

• Like spring-flowering bulbs, these hardy fall bloomers usually rest during the summer.

Although most of the bulbs you're likely to plant will be in the autumn and produce flowers in spring (such as tulips, crocuses and daffodils), there are many that can be planted in spring to produce blooms in late spring or summer including gladioli, calla lilies, dahlias, daylilies, irises and tuberous begonias.

• Depending on where you live, it's generally safe to plant bulbs after the risk of ground frost has passed.
• If you're keen to jump-start the bulbs, you can start them indoors and care for them in a warm spot, then move the plants outside.