Handfuls of bulbs

Guide to bulb planting depths

Find out how to plant bulbs at the correct depth, in our practical guide.

When planting bulbs, it’s important to plant them at the right depth to ensure you get to enjoy the flowers.

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Bulbs that are planted too deeply may produce only foliage at the expense of flowers, or not emerge at all. Too deeply is better than too shallow, though, which puts the bulbs at greater risk of being dug up accidentally, or by squirrels, which will feast on the nutritious bulbs.

Generally, the rule of thumb is to plant bulbs at three times their depth, but there are exceptions to the rule to be aware of. Remember, too, that most bulbs enjoy well-drained soils. If you have heavy soil, plant bulbs that’ll enjoy it, like snake’s head fritillaries, or improve the soil drainage with well-rotted organic matter.

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Find out how deeply to plant different bulb types, below.

If you have heavy soil, plant bulbs that will enjoy it, like snake's head fritillaries, or improve the soil with well-rotted organic matter.

Tulips

Depth: 20cm or three times their depth

Soil: well-drained, neutral or slightly alkaline

Position: full sun, ideally in a sheltered location

When: November to December

Planting tulip bulbs
Planting tulip bulbs

Iris reticulata

Depth: 10cm or twice their depth

Soil: well-drained, neutral to slightly acidic

Position: full sun

When: September to October

Planting iris bulbs in a small terracotta pot
Planting iris bulbs in a small terracotta pot

Daffodils

Depth: 15cm or three times their depth

Soil: moist, well-drained

Position: sun or light shade

When: September to November

Planting daffodil bulbs in a wicker window box
Planting daffodil bulbs in a wicker window box

Fritillaria imperialis, crown imperials

Depth: 30cm or three times their depth

Soil: deep, well-drained soil that has been enriched with well-rotted manure or leaf mould

Position: on its side in full sun

When: September to November

Planting crown imperial fritillary bulbs in the ground
Planting crown imperial fritillary bulbs in the ground

Fritillaria meleagris, snake’s head fritillary

Depth: 10cm or five times their depth

Soil: moist, well-drained and humus-rich

Position: full sun to partial shade, ideally in a cool location

When: September to October, or April while in flower

Chequered, magenta snake's head fritillary flowers
Chequered, magenta snake’s head fritillary flowers

Large globe alliums

Depth: 30cm or three times their depth

Soil: well-drained

Position: full sun in a sheltered location

When: September to October

Planting globe allium bulbs in the ground
Planting globe allium bulbs in the ground

Allium sphaerocephalon

Depth: 15cm or three times their depth

Soil: fertile, well-drained

Position: full sun

When: September to October

Deep-pink Allium sphaerocephalon flowers
Deep-pink Allium sphaerocephalon flowers

Crocus

Depth: 10cm or three times their depth

Soil: well-drained, gritty, poor to fertile soil

Position: full sun

When: spring-flowering crocus from September to November; autumn-flowering crocus from July to August

Crocus bulbs planted in a terracotta pot
Crocus bulbs planted in a terracotta pot

Snowdrops

Depth: 10cm or three times their depth

Soil: moist, well-drained, humus-rich

Position: dappled shade.

When: September to November or just after flowering in spring.

Planting snowdrops 'in the green'
Planting snowdrops ‘in the green’

Hyacinths

Depth: 10cm or twice their depth

Soil: moist, well-drained

Position: full sun

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When: September to October

Pink hyacinth blooms
Pink hyacinth blooms

Layering bulbs

To extend the colour provided by spring bulbs, try layering them in a container, using bulbs that flower at different times. Watch this video on layering crocus, daffodils and alliums.

Faux terracotta pot