by Marilee Henry
Spring is the time when many of our beautiful native "lilies"1 are in bloom in western Washington, including camas, chocolate lilies, and trillium (to name a few!). Though they are all spectacular, my hands-down favorite has got to be great camas, as it is so easy to grow in pots or to let it naturalize, forming swaths of long-lasting sapphire blooms.
Great camas is found only in the western part of our state. It ranges from southern B.C. to northern California, at low to middle elevations in grassy meadows, hillsides, balds, and prairies that are moist in spring but dry out as summer commences. Its close relative, common camas (Camassia quamash), is found on both sides of the Cascades, ranging further east into Montana, Wyoming, and Utah. Both species like somewhat similar habitats, though common camas can occur in dryer, more open areas. Both grow well in most garden soils - great camas even tolerates heavy clay soils if they are not persistently water-logged. Both propagate easily from seed, both vary in color from deep purple-blue to white flowers, and both have edible bulbs2.
Leaves are tall and grasslike. Their numerous flowers open from the bottom upwards on tall terminal spikes, delighting gardeners with a prolonged blossoming period April through May. Though great camas is usually taller (up to 4 feet in height) and has larger bulbs at maturity than common camas, the best distinction between these species is the twisting of the tepals (think "petals") around the ovary as they wither in great camas3. Tepals of common camas wither separately and do not cover the ovary by twisting around it4.
Besides being a stunning bloomer, great camas can be an important part of a pollinator garden, attracting honeybees, bumblebees, mason bees, wasps, beetles, and ladybugs. Voles, rabbits, and most other wildlife tend to ignore the bulbs, though tender young shoots from seeds or immature bulbs may suffer nibbling.
The bulbs, mainly of common camas, were (and still are for some tribes) an important food source for indigenous peoples, being dug up shortly after flowering, cooked over several days in pits, then eaten or dried for future use. Pojar5 provides a good description of indigenous cultivation and harvesting, plus an 1806 journal entry from Meriweather Lewis on his sighting of vast, abundant camas meadows. Mima Mounds Natural Area Preserve south of Olympia, one of Washington's few remaining camas meadows, is well worth a visit this month!6
Plants, seeds, and bulbs of great camas (C. leichtlinii) and/or common camas (C. quamash) may be found at many native plant nurseries and plant sales. Two such sales this month are with WNPS7 on April 14th and Oxbow Farms8 on April 20th.
Seeds should be planted in fall and left outside through winter. Seedlings require regular watering through their first spring growing season. It may take 3 to 4 years from germination to first blooms (when plants have 3 or more leaves), but bulbs and flower spikes will get larger with time. Small bulblets that form on mature bulbs (>5 years old) may be dug up in fall, separated and transplanted. A natural density for starting a camas patch has been suggested as 9 bulbs or plants per square foot. Planting depth to the base of the bulb should be about 3 times the size of the bulb. Great camas will tolerate partial shade, whereas common camas prefers full sun. Be sure to stop watering when blooming has finished, but do not cut off spent flowerheads so that seed capsules can form. Seeds are ripe when the capsules begin to split open.
Note that camas does not require bulb or seed harvesting; left alone in a suitable spot, a patch will become denser and increase in area creating your own camas meadow!
April is Native Plant Appreciation Month. Check out these online lectures focusing on prairie species at the WNPS website9.
And always remember, "You are nature's best hope!" - Doug Tallamy.
Marilee Henry
Kirkland Community Wildlife Habitat Team Member, Washington Native Plant Society (WNPS) Native Plant Steward, Green Kirkland Steward, Finn Hill Neighborhood Alliance Contributor
Recent DNA research has rearranged the traditional "lily" (Liliaceae) family; camas is now in the asparagus (Asparagaceae) family and trillium is in the false-hellebore (Melanthiaceae) family. C. Leo Hitchcock & Arthur Cronquist, "Flora of the Pacific Northwest", 2nd edition, 2018.
WARNING: Bulbs in the genus Camassia, such as great and common camas, are edible. Do not confuse them with similar-looking bulbs of death camas species in the genus Toxicoscordion (previously Zigadenus), all of which are highly toxic!
J. Pojar and A. MacKinnon, "Plants of the Pacific Northwest Coast", 1994, pg 108.
https://www.wnps.org/calendar/central-puget-sound-spring-native-plant-sale