How to grow camassias

Camassias hail from damp meadows and woodland edges in the Pacific Northwest of the US. They were once a food staple for native Indian tribes and were called 'kamas'. Unlike many spring bulbs, camassias will grow in heavy, moist soils, so they're a good choice for areas of your garden where other spring bulbs may not thrive. Completely hardy, they come back year after year. Bees love the flowers, and they're largely untroubled by slugs and snails. They also make good cut flowers. While some varieties can reach around 90cm tall, they have sturdy stems that don't need staking.

Camassias can be planted in borders or pots and look particularly good planted with early perennials such as polygonatum (Solomon's Seal) or dicentra (bleeding heart). They also look wonderful against the acid yellow of euphorbia or the complementary colours of wisteria. However you plant them, plant generously, as they look best grown en masse, creating a haze of colour in a similar way to bluebells. They're perfect for naturalising in grass and look good growing near a stream or pond and under deciduous trees.

How to grow camassias

Plant camassia bulbs in autumn, in humus-rich, moisture-retentive soil in full sun or part shade. They're happy in heavy clay soil and will grow in acid, neutral or alkaline soil. Allow the foliage to die back naturally after flowering and divide congested clumps in summer.

In this short video guide, the experts at Hare Spring Cottage Plants share their top tips for growing camassia, including where to plant them and how to get flowers for longer.

More on growing camassias:

• Five best May-flowering bulbs
• Best bulbs for naturalising

Camassias: jump links

• Planting camassias
• Caring for camassias
• Propagating camassias
• Growing camassias: problem-solving
• Buying camassias
• Best camassias to grow

Where to grow camassias

Grow camassias in moist soil, in sun or part shade. They're excellent for naturalising in grass, but you'll need to let the leaves die down before mowing so choose a spot where you are happy to allow them to do this. Camassias can also be grown in containers, but will need to be well watered in dry periods and kept in a frost-free place over winter.

How to plant camassias

Plant camassia bulbs in autumn, from September to November. Use a bulb planter or a trowel to make a hole for each bulb. Plant the bulbs pointy end facing upwards, at least 10-15cm deep, or around twice the height of the bulb. Space around 10cm apart. Water the bulbs in well.

Watch Monty Don’s guide to planting camassias, in this clip from BBC Gardeners’ World:

If you're growing camassias in pots, use a loam-based compost and a large pot. Plant as deep as you can, closer together than you would in the ground.

Caring for camassias

After watering your bulbs in, they should get enough moisture from rainfall. You could water them in summer if there is a prolonged dry period. Be sure to water bulbs in pots in summer.

Only cut back the foliage when it has completely yellowed and died back – this is important as the dying leaves will feed next year's bulbs. Deadhead the flowers once they've faded, unless you want to save in seed, in which case leave a few spent flowers on the plant.

Camassias don't need feeding but those growing in a border can be mulched in autumn. This will also help to protect the bulbs over winter if you live in a very cold area.

If your camassias are becoming congested and not flowering well, split the clumps in July and August and replant the bulbs further apart or in a new area.

Move bulbs in pots to a frost-free place in winter.

How to propagate camassias

The easiest way to propagate camassias is to split clumps of bulbs when they are dormant, in summer. Separate the clumps and replant them further apart or elsewhere in the garden. You can also remove the offsets that have formed around the main bulbs and replant them.

Alternatively, collect seed when it's ripe in early summer (you'll need to remember not to deadhead). Sow in a seed tray and leave to germinate in a cold frame. New plants can take up to three years to flower.

Growing camassias: problem solving

Camassias are mostly trouble-free. Poor flowering is usually due to lack of moisture in the soil, or an overcrowded clump. If it's the latter, lift and divide the clump in summer.

Varieties of camassia to grow

Camassia quamash (common camassia) – a short, early flowering variety that's excellent for naturalising in grass. It has dark, purple-blue flowers with vivid yellow stamens.
Height x Spread: 30cm x 10cm

Camassia liechtlinii – tall, loose spires of white, blue or pale pink flowers, depending on the variety. A popular choice for a border.
H x S: 90cm x 10cm

Camassia cusickii 'Zwanenburg' – a rare variety with blue petals and a paler stripe down the middle.
H x S: 75cm x 10cm