Tall larkspur is a native North American perennial wildflower that brings gentian blue spikes of showy blooms to the summer garden from July through September. Growing 4 to 6 feet tall in hardiness zones 5 through 7, this species thrives in full sun with moderate moisture and moderate care. Native to Eastern North America from Pennsylvania and Ohio south through the Appalachians into northern Alabama, with isolated populations in the Ozarks, tall larkspur carries the heritage of cool-climate woodland edges into the garden, where it attracts butterflies and resists browsing deer.
Full Sun
Moderate
5-7
72in H x 24in W
—
High
Hover over chart points for details
Rising 4 to 6 feet with loose terminal racemes of gentian blue flowers, tall larkspur commands attention in the mid-to-late summer garden when many perennials are fading. Unlike many hybrid delphiniums that sulk in heat and humidity, this species shows better tolerance for warmer, more humid conditions while still performing best in cool summer climates. The tall, elegant spikes bloom continuously from July through September, especially if you remove spent flower heads, sometimes rewarding dedicated deadheading with a sparse second flush in autumn.
Tall larkspur serves as a striking vertical accent in perennial borders and cottage gardens, where its tall spikes of gentian blue flowers provide bold color during the mid-to-late summer months. The showy blooms attract butterflies and other pollinators, making it valuable for wildlife gardens and plantings designed to support native insect populations. Its deer resistance also makes it a practical choice for gardens where browsing pressure limits the palette of available perennials.
No timeline data available yet for this variety.
Tall larkspur may be grown from seed. Start seeds indoors in late winter, 6 to 8 weeks before the last spring frost, in cool conditions around 65 to 70 degrees Fahrenheit. Sow seeds on the soil surface or press them lightly into the soil, as they benefit from light for germination.
Transplant seedlings outdoors after the last frost has passed, spacing plants 12 to 24 inches apart. Harden off seedlings gradually over a week to acclimate them to outdoor conditions before planting in their final location.
Tall larkspur can be direct sown in late fall or early spring in the garden, pressing seeds lightly into the soil in their permanent location.
Remove spent flower spikes throughout the blooming season to encourage continued flowering and maintain plant appearance. Cutting back the entire plant after frost in late autumn or early winter helps tidy the garden and reduces disease pressure; taller plants may benefit from staking or support structures to prevent wind damage to the tall stems.
Enter your ZIP code to see a personalized growing calendar for this plant.
“Delphinium exaltatum is a native wildflower with deep roots in Eastern North American woodlands and rocky slopes. Found naturally from Pennsylvania and Ohio southward through the Appalachian Mountains into northern Alabama, the species also exists in several small, isolated populations in the Ozarks of south central Missouri, where it grows on wooded limestone slopes above the Jack's Fork and Current Rivers in Shannon and Howell Counties. This distribution tells the story of a plant that has adapted to cool, moist mountain microclimates over centuries, and its presence in isolated pockets across the landscape speaks to both its specific ecological requirements and the ecological changes that have fragmented its range.”