Doubtful Knight's-Spur (Delphinium ajacis)

common name: 
Doubtful Knight's-Spur, Rocket Larkspur, Annual Larkspur
 | 
scientific name: 
Delphinium
 
ajacis
Purple wildflowers in a lush green meadow.

Doubtful Knight's-Spur (Delphinium ajacis) produces striking spikes of blue, purple, pink, or white flowers that provide vibrant color and attract pollinators during late spring and early summer. This photo was taken in the Backyard Farmer Garden in Lincoln, Nebraska. 

Image Creadit: 
Trey Lamkins, Graduate Research Assistant

Doubtful Knight's-Spur (Delphinium ajacis), commonly known as Rocket Larkspur, is a cool-season annual prized for its tall spikes of colorful flowers and finely textured foliage. Native to the Mediterranean region but widely cultivated throughout North America, it blooms in late spring and early summer with dense flower spikes in shades of blue, purple, pink, and white. The nectar-rich flowers attract butterflies, bees, and hummingbirds, making it a valuable addition to pollinator gardens.

Charecteristics
Plant type: 
Annual
Hardiness Zones: 
2, 3, 4b, 5a, 5b, 6a, 7, 8, 9, 10, 11
Light Needs: 
Full Sun
Water Needs: 
Moist
Space Requirements: 
12 inches – 3 feet
Height Requirements: 
2–4 feet
Spread Requirements: 
1–2 feet
Maintenance Requirements: 
Low
Bloom Color: 
White
Pink
Blue
Purple
Bloom Time: 
Spring
Summer
Leaf Color: 
Green
Wildlife Attraction: 
Hummingbirds
Butterflies
Companion Plant Tolerance: 
Rabbit
Deer
Uses: 
Annual
Ground Cover
Rain Garden
Varieties