Common camas

Sun

Full sun or light partial shade; flowering is best in sun.

Water

Keep moist during spring growth and flowering. Once the leaves die back, reduce watering; avoid prolonged summer waterlogging.

Soil

Fertile, moisture-retentive loam or clay that drains sufficiently during summer dormancy. Tolerates seasonally wet ground, but not permanent submersion.

Height

1-2.5 ft (0.3-0.75 m)

Spread

0.5-1 ft (0.15-0.3 m) per clump

Flowers

Late spring to early summer; usually blue to violet-blue, occasionally white.

Foliage

Narrow, grass-like green leaves emerge in spring and yellow and die back after flowering.

Growth

Moderate; clumps gradually enlarge, and seedlings take several years to flower.

Care needed

Low

• Plant bulbs in autumn about 4-6 in (10-15 cm) deep and 4-6 in (10-15 cm) apart.
• Water during dry spring weather while leaves remain green.
• Top-dress with a thin layer of compost in autumn; rich feeding is usually unnecessary.
• Leave foliage intact until it has yellowed completely.
• Lift and divide crowded clumps after the foliage dies back, replanting promptly.

Pruning. Remove spent flower stems if you do not want seedlings, or leave them until the seed ripens. Cut away leaves only once they are fully yellow or brown.

Autumn

Plant bulbs and top-dress established clumps lightly with compost.

Early spring

Check emerging shoots for slug and snail damage.

Spring

Water during dry spells so the soil stays moist while plants are actively growing.

Late spring

Remove fading flower stems to limit self-seeding, or retain them for seed.

Summer

Allow leaves to die back naturally; delay mowing meadow areas until this is complete.

Late summer

Divide crowded dormant clumps if necessary and replant without letting bulbs dry out.

• Plant broad drifts through a spring meadow, with mowing delayed until the leaves die back.
• Thread bulbs among later-emerging perennials that conceal the fading foliage.
• Use beside a seasonally damp swale or pond margin, above the permanently saturated ground.
• Combine with other spring bulbs in informal borders for upright blue accents.

Garden styles it suits: Native meadow, Wildflower, Cottage garden, Pollinator garden, Pacific Northwest woodland and New perennial (prairie).

Plant it with: Prairie smoke, Shooting star, Tufted hair grass, Siberian iris, Hardy geranium and Lady's mantle.

Wildlife: Flowers provide pollen and nectar for bees and other visiting insects. Deer often leave established plants alone, but browsing and bulb losses to rodents can still occur.

• Slugs and snails can damage emerging leaves: inspect young growth and use barriers, hand-picking or locally approved iron phosphate bait where needed.
• Bulb rot can develop in stagnant, waterlogged soil: improve drainage or move bulbs away from permanently wet sites.
• Poor flowering can follow deep shade or early leaf removal: provide more sun and leave foliage until it dies naturally.
• Premature browning can result from spring drought: water deeply during active growth rather than waiting until flowering.

Camassia quamash is not known to be toxic to people; its bulbs have a long history as food after proper preparation. It is not generally regarded as poisonous to cats, dogs or horses, although species-specific veterinary information is limited. Do not let pets eat bulbs, and do not eat unidentified wild bulbs: confusion with highly poisonous death camas can be fatal.

• Great camas (Camassia leichtlinii)

  Usually taller and more robust, with larger flower spikes. Its fading flower segments twist together over the developing fruit, whereas those of common camas generally remain separate.

• Meadow death camas (Toxicoscordion venenosum)

  Has cream to yellowish-white flowers rather than the usual blue of common camas, often in a denser, sometimes branched cluster. Both have grass-like leaves and bulbs;

• Wild hyacinth (Camassia scilloides)

  An eastern and central North American species, usually with paler blue or whitish flowers in a relatively loose spike. Pale-flowered plants can be difficult to separate confidently without a botanical key.

Both Camassia and quamash derive from Indigenous North American names for camas, whose bulbs were an important traditional food.

Propagation. Separate bulb offsets after the leaves die back and replant promptly. Alternatively, sow ripe seed outdoors in pots or a prepared bed; winter cold encourages germination, and seedlings usually need several years to reach flowering size.

Accepted botanical name

Camassia quamash

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alberta, British Columbia, California, Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming.

Measured

Soil pH 5.7 to 7.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.