How to Grow and Care for Flowering Bulbs Corms Tubers and Rhizomes
By: Linda Peppin

Bulb is a general term used for plants which have a food storage organ which allows them to grow and flower quickly once the ideal conditions are available. There are four types of "bulb": true bulbs, corms, tubers and rhizomes.

The Gardener can find a huge and colourful selection of bulbs for every season of the year. Most are fully hardy but some, such as Cannas, need to be lifted for the winter. Dahlias dislike wet conditions so many people also lift these to avoid the worst of the winter weather. Below are a few examples of the bulbs which can be grown in each season.

Spring

Daffodil, Scilla, Tulip, Iris, Chionodoxa, Anemone

Summer

Allium, Galtonia, Lily, Canna, Gladioli, Dahlia

Autumn

Colchicum, Amaryllis, Nerine, Cyclamen hederifolium, Eucomis. Sternbergia

Winter

Cyclamen coum, Winter aconite, Snowdrop, Hippeastrum, Hyacinth

Some tips when buying bulbs:

Buy early and plant immediately
Always choose plump, large bulbs
Ensure the outer skin is intact and clean
Do not buy bulbs already in growth
The growing point should be firm
Squeeze the bulb to check it is firm
A good bulb is even in colour with no blotches
Buy snowdrops "in the green"*

Planting bulbs:

Ensure soil is free draining
Add well-rotted compost to sandy soils
For naturalisation, plant in autumn
Plant tulips four times their own depth
Most bulbs prefer a sunny site
Ensure bulbs are planted pointing upwards
Dig heavy clay soil and add coarse grit
Add organic matter to the soil when resting
Plant most bulbs three times their own depth
Plant rhizomes just below the surface
Plant snowdrops "in the green"*
Most bulbs are suitable for containers

Aftercare:

After flowering the reserves of the bulb are built-up from the leaves. Do not remove them until they dry out
Lift and divide clumps after a few years
After flowering feed with tomato fertiliser at half the strength used for tomatoes
Mulch during the resting period
Division should be done in the resting period

Storing bulbs:

Most bulbs can be stored
Check every few weeks and remove any which are rotting.
Clean off soil and remove foliage/roots. Ensure bulbs are clean and dry, dust with fungicide. Place in paper bag and label. Keep cool and dry.

Forcing Prepared Hyacinths:

Buy as soon as possible
Plant in a bulb fibre compost, close together with the tips just showing above the compost
Water so the compost is damp
Place in cool, dark place
When the bud is visible bring into the light
A cool room is best

Problems:

Bulb Blindness: Buds fail to flower.

Caused by overcrowding and a lack of nutrients. Lift and replant in a fertilised soil.

Basal Rot: A brown stain around the scales of the bulb.

There is no cure, dispose of safely.

Bulb Flies: To avoid, pull soil over the neck of the bulb as the leaves die down.
Storage Rot: Discard rotting bulbs to avoid spreading. Dust with fungicide.

The Bulb Gardening Year

Spring

Replant pot-grown bulbs bought for an instant effect
Plant snowdrops and snowflakes bought "In the green"*
Check for any signs of grey mould and spray with a fungicide to reduce infection
Stake tall bulbs
In late spring, plant out tender bulbs like gladioli and begonias
Deadhead flowers to concentrate energy into the bulbs
In late spring, clear away yellowing foliage to eliminate the homes for slugs and snails
Store container bulbs in a cool out of the way place
Feed potted bulbs with liquid fertilizer
Water indoor cyclamen as they get new leaves. Feed every two weeks

Summer

Lift and divide overcrowded clumps as the leaves die down
Collect dry seed in paper bags and store in a cool dry place
Clear away dying foliage to tidy the border and avoid the spread of disease
Rake over holes left in the soil by old bulb stems to lessen the chance of insects laying eggs in the tunnel. Mulch the whole area
Plant out pot-grown summer and autumn-flowering bulbs to fill gaps in the border
Re-pot winter and spring bulbs
Tie gladioli and tall dahlias to stakes for support
Buy new bulbs from your local garden centre or order from bulb catalogues

Autumn

Plant commercial bulbs
Prepare heavy or compacted soil for planting by digging deeply and adding grit. Sprinkle a general-purpose fertilizer into the planting hole, and plant the bulbs at the required depth
Early autumn, plant containers with specially-prepared bulbs to flower in midwinter
Mark the location of your bulbs with labels to avoid disturbance later
Lift dahlias and gladioli and prepare for winter storage

Winter

Clear away any old foliage that might impede fresh growth. Mulch the site
Add a general purpose fertilizer to the surrounding soil
Store bulbs in a box in a cool, frost free place and check regularly for disease
Move groups of bulbs. Dig up the clump and place in the new position
Sow commercial bulb seed
If leaves show signs of disease lift the whole plant and dispose of it
Bring forced bulbs into a cool place to flower
Order late summer flowering bulbs

* "In the Green": Plants are lifted just after flowering with the leaves still intact. Ensure they never dry out. Plant back at their original depth. The papery sheath around the bulb should just be visible.

Linda Peppin runs The Gardening Register which is an easy to follow, informative website covering all aspects of gardening. For more gardening related articles visit her site at http://www.gardeningregister.co.uk.

The articles on her website must not be copied or used elsewhere.

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