This elegant, long-blooming perennial wildflower attracts hummingbirds and is as suitable for formal gardens as it is for wildflower meadows. It begins blooming in mid-summer and often continues to produce showy blooms into late autumn, making it an important source of mid-summer nectar for pollinators. The handsome spikes of gentian-blue flowers are an excellent focal point in gardens as well as in cut-flower arrangements. The coarse-textured, deeply cut foliage forms an attractive mound not unlike that of wild geranium. According to an online Epic Gardening article by Kelli Klein, dill, fennel, and parsley are host plants for swallowtail butterflies. Planting larkspur as a companion to these plants will ensure food for the emerging butterflies.  
 
As its common name indicates, tall larkspur typically grows 4 to 6 feet tall in full sun and in average to dry, well-drained soils ranging from sandy loam to clay loam. Full sun is preferable, although a touch of afternoon shade is usually welcome. Selecting a site with good drainage and aeration is essential to avoid the development of root rot and powdery mildew. The tall stalks benefit when protected from strong winds, and they may also need staking or natural support from nearby plants. 
 
Native to the central and eastern US, tall larkspur is rarely seen in Ohio and is listed as potentially threatened. Its beauty and stature tempt many plant lovers to harvest the flower from the wild, and overgrowth by woody species also contributes to the plant’s scarceness. In domestic landscapes, it will reseed readily and spread by rhizomes to quickly claim its space. Removing spent flower spikes helps encourage additional blooms, which may appear sparsely in the fall until the first frost. 
 
Delphinium is in the Buttercup family, and this species is taller, blooms later, and has more abundant foliage than most other native plants in its genus. Delphis means “dolphin,” referring to the shape of the flower bud, while the specific epithet means “very tall.” Tall larkspur contains alkaloids, including delphinine and ajacine, which are poisonous to humans, pets, horses, and livestock. Ingesting any parts of the plant will produce a variety of symptoms, from burning of the mouth to paralysis of the respiratory system. Wearing gloves is advisable, as contact with the plant can cause skin irritation. 
 
Native habitats include prairie remnants, dry and open woods, slopes, edges of woods, ravines, and thickets. Use in borders, cut-flower gardens, wildflower meadows, cottage gardens, micro prairies, and massed or in small groupings. It pairs nicely in native gardens or backs of borders with coneflowers, black-eyed Susans, blue lobelias, and asters. 
 
Plant Characteristics: 
Grows 4-6’ tall and 1-2’ wide. 
 
Grows in full to part sun. 
 
Prefers moderate to dry, well-drained soils, including loamy sand and clay. Overly rich soils may cause root rot. 
 
Dense, narrow clusters of purplish-blue and occasionally white flowers form at ends of stalks July-August. Each flower is up to 1” long with five sepals, one of which is curved backward into a “spur.” The two lower petals may have whitish hairs. 
 
Rounded, deep green leaves on lower stalk are divided into 5 parts; each part has 3-7 lobes. Mid-stem leaves have fewer lobes and shorter petioles. There are no leaves on the upper portion of the stem. 
 
Erect, green stem is round, smooth, and somewhat fleshy. 
 
Wildlife Value: 
Host plant to 10 species of Lepidoptera larvae, including the bilobed looper moth pictured here. Tall larkspur attracts long-tongued bees, butterflies, and hummingbirds.  
 
Medicinal, Edible, and Other Uses: 
Warning: All parts of the plant are highly poisonous.