Guide to Bulb Planting Depths

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

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Iris reticulata

Depth: 10cm or twice their depth

Soil: well-drained, neutral to slightly acidic

Position: full sun

When: September to October

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Daffodils

Depth: 15cm or three times their depth

Soil: moist, well-drained

Position: sun or light shade

When: September to November

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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

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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

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Large globe alliums

Depth: 30cm or three times their depth

Soil: well-drained

Position: full sun in a sheltered location

When: September to October

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Allium sphaerocephalon

Depth: 15cm or three times their depth

Soil: fertile, well-drained

Position: full sun

When: September to October

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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

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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.

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Hyacinths

Depth: 10cm or twice their depth

Soil: moist, well-drained

Position: full sun

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When: September to October

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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.