Types Of Flower Bulb

What are the Types of Bulb?

Gardeners refer to several distinct plant structures as flower bulbs in everyday conversation. 

• True bulbs – Rounded, pointed top, flat base where roots grow: Allium, Anemone, Bluebell, Daffodil, Hyacinth, Snowdrop, Lily, Tulip
• Corms – Similar to bulbs, with buds on top and roots from the base: Crocus, Gladioli
• Tubers – Swollen roots like Dahlia, or swollen stem bases: Cyclamen, Aconite
• Rhizomes – Horizontal, swollen stems, growing on or just below the soil: Bearded Irises, Lily-of-the-valley, Cannas

From a planting season perspective, bulbs / corms / tubers / rhizomes are handled one of 4 ways:

• Dry, dormant bulbs are planted in Autumn
• A limited range of bulbs are planted in growth (In the Green), in early Spring
• Tender species like Dahlias are best planted into warm soil in late Spring
• Some late season bulbs like Nerines and Colchicums can be planted until the end of Summer

Spring vs. Summer Bulbs

Two groups, Spring and Summer flowering, are often referred to for convenience: Spring bulbs are mainly planted in Autumn, and Summer bulbs during the growing season from mid-Spring.

Spring-Blooming Bulbs:

• Always Winter hardy.
• Planted in Autumn to bloom the following Spring (unless planted 'in the green' in Spring)
• Maintenance: None, unless old clumps need division. Most will bloom annually, some for many years.
• Examples: Allium, Anemone, Bluebell, Daffodil, Hyacinth, Snowdrop, Lily, Tulip

Summer-Blooming Bulbs:

• May need protection in Winter.
• Planted in Spring to bloom that Summer
• Maintenance: Can be treated as annuals or dug up and stored in a frost-free area over winter for replanting the following spring. Many varieties survive Winter under mulch.
• Examples: Dahlia, Canna, Gladiola, tuberous Begonias.

Read about How to Plant Flower Bulbs.