Delphinium tricorne aka Dwarf Larkspur

Delphinium tricorne has two names: dwarf larkspur and spring larkspur. It belongs to the buttercup family. This herbaceous perennial has soft stems and lives for years. It grows wild in the north-central and eastern United States. Its range runs from Pennsylvania and Minnesota to Oklahoma and Georgia. Wild plants grow in rich, moist woods and thickets. They also grow in ravines, on rocky wooded slopes, and on cliffs.

Plants grow about 1–3 feet (0.30–0.91 metres) tall. Missouri Botanical Garden lists a height of 2 feet (0.61 metres). They spread 1–1.5 feet (0.30–0.46 metres) wide. The upright stems are fleshy, round, and hairy. Most leaves form a cluster near the ground. These green or gray-green leaves have five deeply cut lobes. Each lobe splits again into smaller parts. A few leaves grow along the flower stalk. These leaves alternate, growing one at a time along the stalk.

The flowers grow in loose racemes, or stalked clusters. They may be blue, violet, purple, or white. Some flowers have a white center. Five showy sepals sit around four small petals. The upper sepal extends back to form a spur. Sources disagree on when the flowers open. Missouri Botanical Garden gives April through May as the bloom time. Chicago Botanic Garden gives May through June for bloom. NC State gives July through September for bloom. The fruit forms three green, horn-shaped pods called follicles. These pods split open to shed their seeds. NC State gives August through October for seed release.

Grow this plant in rich soil with plenty of organic matter. Keep the soil moist, but let excess water drain away. Full sun suits it, with afternoon shade in hot climates. It grows in neutral soil and tolerates alkaline soil too. Sources support USDA zones 4–7 for this plant. Cool summers suit it better than hot, humid ones. Shelter plants from strong wind and heavy rain. Taller flower stems may need stakes to support them. Plants can grow from seed and may reseed. Chicago says this plant lives for only a few years.

Use dwarf larkspur in borders, woodland gardens, or small groups. Cut flowers for display; they also draw butterflies and hummingbirds. Deer and rabbits tend to avoid the plant. Problems include powdery mildew and botrytis blight. Leaf spots and crown rot can also cause problems. Slugs, snails, aphids, and mites can cause damage. Borers and leaf miners can harm the plant too. Poor drainage raises the risk of crown rot. All parts are poisonous; do not eat any part. Poisoning can cause vomiting, weakness, and convulsions, or fits. It can also stop breathing and cause death. It poses risks to people, cats, dogs, and horses. Chicago also warns against growing it to make honey.