Delphinium nuttallianum

Common Names

Twolobe Larkspur, Nuttall's Larkspur, Nuttal's Larkspur, Two-Lobe Larkspur, Low Larkspur, Yellow Larkspur, Upland Larkspur

Summary

Delphinium nuttallianum, commonly called upland larkspur or two-lobe larkspur, is a perennial herb in the Ranunculaceae native to western North America from British Columbia to New Mexico, typically occupying dry, gravelly ground from sagebrush deserts to ponderosa pine regions. It grows as an erect plant 10–40(70) cm tall with a reddish base and leaves mainly on the lower quarter of the stem; basal leaves are 2–6 with 5–21 ultimate lobes, while the dense terminal raceme carries 20–90 bluish purple flowers, the five sepals with lateral sepals reflexed, a spur 8–23 mm long, and blue to purple lower petals partly exposing the stamens; flowers may be white to pink in rare cases. Fruits are follicles containing numerous seeds; flowering occurs in spring to early summer, and the species inhabits open coniferous woods, grassy sage scrub, meadow edges, and well-drained streamsides at elevations around 1800–2600 m. The plant is toxic to livestock.

In cultivation, it tolerates dry to mesic conditions and prefers well-drained soils, with a slow growth habit that can persist in a seedbank; a documented propagation protocol describes seed-based propagation involving cold moist stratification (storage 40°F and 40% RH), sowing in liner trays with a peat:vermiculite:perlite mix, topping with pea gravel, wintering outdoors before March germination, seedlings moved to a lath house in June and overwintered before planting as 1.5-inch plugs the following May, and suggests drainage improvements where needed. For landscape use, it can be planted in naturalized areas or formal beds, and caution is warranted in areas with livestock due to cattle toxicity, although wildlife may browse it.

Lifecycle

Annual, Biennial, Perennial

Height

0.5-2.5 feet

Spread

8-12 inches

Hardiness Zones

Zones 4a-9b

Sunlight Requirements

Ideally full Sun. Tolerates partial shade

Soil Type

Well-drained, dry, gravelly soil

Soil Drainage

Well-drained soil

Bloom Color

Blue to purple

Bloom Time

Spring to Summer

Foliage Color

Green

Fall Foliage Color

Green

Leaf Lifecycle

Deciduous

Growth Rate

Slow

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds

Attracts Wildlife

Attracts bees, hummingbirds, butterflies, moths, and birds