Cusick's camas

Sun

Full sun or partial shade; flowering is best with plenty of spring light.

Water

Keep the soil moist during spring growth and flowering. Reduce watering once the leaves yellow; avoid waterlogged soil, especially during summer dormancy.

Soil

Fertile, humus-rich soil that retains spring moisture but drains freely. Tolerates clay if it does not remain waterlogged.

Height

2-3 ft (0.6-0.9 m)

Spread

1-2 ft (0.3-0.6 m) per established clump

Flowers

Late spring to early summer; pale powder-blue, star-shaped flowers open progressively up upright spikes.

Foliage

Broad, strap-shaped, blue-green leaves emerge in spring and yellow and disappear after flowering.

Growth

Moderate; clumps enlarge gradually through bulb offsets.

Care needed

Low

• Pollinators
• Deer resistant
• Cold hardy
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   2.5 ft (0.75 m)

   full size

About 1 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the US

Growth rate

Moderate

• Plant bulbs in autumn about 4-6 in (10-15 cm) deep and 6-8 in (15-20 cm) apart.
• Water during dry spring weather while leaves and flower stems are growing.
• Apply a thin layer of garden compost around emerging shoots in spring; rich soil needs little additional feeding.
• Allow the foliage to yellow naturally, and avoid routine summer watering after it dies back.
• Divide crowded clumps during summer dormancy, replanting the bulbs promptly.

Pruning. Remove spent flower stems after flowering if you do not want seedlings. Leave all green foliage intact, then remove it once it has yellowed and withered.

Autumn

Plant bulbs in groups in moisture-retentive, well-drained soil.

Early spring

Apply a light compost dressing and check emerging shoots for slug damage.

Spring

Water during prolonged dry spells while the plants are actively growing.

Late spring

Enjoy the flowers; remove faded spikes unless you want seed.

Summer

Let the leaves die back before clearing them or mowing surrounding grass.

Late summer

Lift and divide congested clumps while dormant, then replant immediately.

• Plant in repeated groups through a mixed border for pale blue vertical accents before summer perennials reach full height.
• Naturalise in meadow grass that can remain uncut until the camas foliage has died back.
• Use at the sunny edge of deciduous trees, where bulbs receive spring light before the canopy closes.
• Pair with later-growing perennials to conceal yellowing foliage and fill the summer gap.

Garden styles it suits: Cottage garden, English country, Wildflower, New perennial (prairie), Blues and silvers and Pacific Northwest woodland.

Plant it with: Hardy geraniums, Lady's mantle, Peonies, Siberian irises, Daffodils and Astrantias.

Wildlife: The flowers provide pollen and nectar for bees and other visiting insects.

• Slugs and snails can damage emerging leaves: check young shoots during damp weather and use wildlife-conscious slug controls where necessary.
• Bulb rot in waterlogged soil: improve drainage or move bulbs to a site without standing winter or summer water.
• Poor flowering in deep shade or overcrowded clumps: move to a brighter position and divide during dormancy.
• Reduced flowering after early mowing or leaf removal: leave foliage intact until it has completely yellowed.

Not known to be toxic to people, cats, dogs or horses, although species-specific animal safety information is limited. Do not treat the bulbs as food: edible camas can be confused with highly poisonous death camas, and this species is grown as an ornamental.

• Common camas (Camassia quamash)

  Usually shorter, with narrower leaves and deeper blue flowers; Cusick's camas typically has broader, blue-green foliage and paler blue blooms.

• Large camas (Camassia leichtlinii)

  Often taller, with more evenly symmetrical flowers. Its spent flower segments characteristically twist together over the developing fruit; those of Cusick's camas do not.

• Meadow death camas (Toxicoscordion venenosum)

  Has cream to greenish-white flowers rather than pale blue ones. Leaves and bulbs alone are not safe identification features; death camas is highly poisonous.

Camassia comes from a North American Indigenous name for camas, and cusickii honours the American botanist William Cusick.

Propagation. Separate bulb offsets from established clumps during summer dormancy and replant promptly. Seed can be sown fresh in an outdoor pot and exposed to winter cold; seedlings take several years to flower.

Accepted botanical name

Camassia cusickii

In the US and Canada

Native in the lower 48 states.

Native range

Idaho and Oregon.

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