Bulb · Asparagaceae
Common Camas
Camassia quamash
Tall spikes of blue and violet rising over wet spring ground.
Full sun
Every 3–7 days
USDA 3–8
1–4 ft · 0.3–1.2 m
Overview
Picture a damp spring meadow brushed blue: that is common camas (Camassia quamash), a hardy North American bulb of the Asparagaceae family. Slim leaves and tall flower spikes push up out of bare ground, open into blooms of blue and violet, then carpet the wet ground in color from March to June.
The plant lives by a clean yearly beat. Leaves and stalks climb and flower through cool, wet spring, then the whole thing dies back and the bulb drops into rest underground, sitting out the dry heat in summer dormancy. Spring growth wants the soil wet; the resting bulb wants it dry. It is easy, perennial, and strictly an outdoor plant.
Long valued well beyond the garden: Native American peoples cooked the starchy bulbs as food. One serious caution rides along with that, though, since the edible bulb is the near image of death camas, which is deadly poisonous. Never dig and eat a wild bulb without an expert to confirm it.
Care
The short version: give common camas full sun and moist, humus-rich soil while it grows and flowers in spring, then let it dry out and rest through summer. Set the bulbs in fall, leave the foliage to die back on its own, and divide a clump only when crowding cuts its bloom.
Light
Plant camas where the sun pours down all day; full sun brings the heaviest flush of blue-violet spikes. It will take partial sun or light, broken shade, but push it into deep shade and you get leaves with few or no flowers to top them.
Water
Through its spring growth and bloom the bulb drinks like the wet meadow native it is: keep the soil evenly moist, watering before it dries as the stalks climb and flowers open. When the foliage dies back into summer rest, pull the water right back and let the dormant bulb sit on the dry side.
Soil
Give it well-drained yet moist, humus-rich ground worked full of organic matter. It is easy about acidity, settling in anywhere across a pH of 5.5 to 7.5, so long as water can move through and not pool around the resting bulb.
Temperature
Tough across zones 3 to 8, common camas shrugs off cold down to about 10°F (-12°C). As the air climbs toward 86°F (30°C) the top growth fades and the bulb retreats below ground to wait out the heat.
Humidity
Outdoor air humidity is no concern here. What the plant cares about is moisture at the roots while it grows in spring; an average atmosphere suits it fine.
Feeding
Feed lightly and only once. Mix a balanced bulb fertilizer or some compost into the soil at planting in spring, and that single feed carries the bulb through the season.
Pruning
No routine cutting. Let the spent leaves die back naturally after the spikes fade so the bulb can recharge for next year. Snip off old flower stalks only when you want to stop it self-seeding.
Repotting
Leave it be; camas rarely needs lifting. Step in to divide a clump only when it grows so dense the flowering drops off, or when offsets crowd up to the soil surface.
Size & spacing
Flower spikes reach 1 to 4 feet (30 to 120 cm) tall, while each clump spreads 12 to 24 inches (30 to 60 cm) across. Left undisturbed it knits into natural drifts over the years.
When to plant
Common camas keeps a strict calendar. Tuck the bulbs in during fall so they root over winter, watch the spikes climb and open from March to June, then let the leaves yellow and fade as the bulb settles into its summer rest.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant bulbs in fall; sow seed outdoors in fall or spring
- Harvest: Spring (March to June)
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
A healthy camas mostly looks after itself, but two troubles turn up: lush leaves that refuse to throw up flower spikes, and soft, tunneled bulbs found hidden below the soil. Both read clearly once you know the signs.
Soft, Holed Bulbs Below the Soil Line
Lift a struggling clump and the bulbs feel mushy, bored through with grub tunnels, or slick with rot. Narcissus bulb fly larvae chew their way inside, while soggy, badly draining ground left wet through the resting months sets the bulbs decaying.
Fix:
- Remove and destroy infested or rotten bulbs
- Improve soil drainage for summer dormancy
- Avoid leaving wounded bulbs in waterlogged soil
Leaves Stand Tall, But No Spikes of Blue
Strong green foliage rises with nothing to crown it: the tall flower spikes and their blue-violet blooms fail to appear. Deep shade is the usual culprit, followed by packed clumps fighting over root space, or young plants too immature to bloom yet.
Fix:
- Site in full sun for best flowering
- Lift and divide crowded clumps of bulb offsets after foliage dies back
- Be patient with seed-grown plants, which need several years to bloom
Toxicity
True common camas carries no toxin for people or animals, and its bulbs fed people for generations. The one real hazard is not poison in the plant itself but misidentification, the trap of mistaking it for its deadly look-alike.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Not poisonous to cats; a curious nibble at the spring foliage is no cause for worry.
Dogs None
Not poisonous to dogs; one that digs up and gnaws a bulb should come away fine.
Horses Safe
No toxicity is reported for horses that graze the leaves or stalks.
Rabbits Safe
Rabbits can browse the green growth with no harm; there is no toxin to trouble them.
Livestock Safe
Grazing cattle, goats, and sheep face no risk from true common camas.
Birds Safe
No known hazard to birds.
People Safe
The cooked bulbs were a staple food of Native American peoples and are safe once correctly identified; the one real danger is confusing them with deadly death camas, so never eat a wild bulb without an expert's confirmation.
The true danger is misidentification: edible camas bulbs closely resemble the highly poisonous death camas (Toxicoscordion/Zigadenus). Never forage or consume wild bulbs without expert identification.
Varieties
A couple of selected forms sharpen what the wild plant already does well, one prized for patterned, cream-edged leaves and the other for tall stems of deep blue flowers.
Camassia quamash 'Blue Melody'
Carries deep blue-violet flowers above leaves edged in cream, the variegated foliage already patterned and on show before the spikes open.
Camassia quamash 'Orion'
Lifts deep blue flowers on tall stems, a strong choice for naturalizing in drifts across a damp meadow.
How to propagate
Camas multiplies several ways, from prising apart the bulb offsets clustered round a parent to scattering seed for a slow, self-sown spread. Most routes are easy; the wait runs from a season or two up to a few years.
Offsets & pupsEasy
After foliage dies back in summer dormancy · 1 to 2 seasons
Once the foliage has died back into summer dormancy, ease up a clump and twist away the bulb offsets ringing the parent. Tuck them into moist, humus-rich ground; they settle over 1 to 2 seasons and are the fastest route to a spreading drift.
Bulbs & cormsEasy
Fall · 1 to 2 seasons
Set the dormant bulbs into moist, humus-rich earth in fall so they root through winter and rise to bloom the following spring. Allow them 1 to 2 seasons to build toward a full display.
SeedModerate
Sow outdoors in fall or spring · Up to 3 years to flower
In a damp meadow it self-seeds with ease; you can scatter your own outdoors in fall or spring. Seedlings are slow, taking up to 3 years to reach blooming size.
DivisionEasy
During summer dormancy · 1 to 2 seasons
Split an established clump while it rests in summer dormancy to keep it vigorous and widen the drift. The divided pieces re-root within 1 to 2 seasons.
Myths
Every camas bulb is safe to eat, since Native American peoples ate camas.
Edible common camas is a near twin of death camas (Toxicoscordion/Zigadenus), whose bulbs are poisonous and can kill. The two are easiest to mix up out of bloom, once the flower color that separates them is gone. Never eat a wild bulb without expert identification.