Black Knight Sweet Pea is a stunning heirloom variety of Lathyrus odoratus that lives up to its dramatic name with deep, dark blooms that emerge from spring through summer. These tall climbers reach 6 feet and produce fragrant flowers over 84 days from seed to first bloom, thriving in full sun with moderate water. Deer leave them untouched, and pollinators visit eagerly, making this a show-stopping addition to any sunny garden or trellis.
6
Full Sun
Moderate
2-11
72in H x 8in W
—
High
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The dark, richly colored blooms are what gardeners remember most about Black Knight, a true heirloom that has earned its place in cottage gardens for generations. At 6 feet tall with a narrow 8-inch footprint, it's built for vertical gardening and creates dramatic height without consuming much ground space. Butterflies and bees visit constantly, while the long bloom window from March through August means weeks of cut flowers and garden color.
Black Knight sweet peas are grown primarily for their flowers, which are prized as cut flowers for arrangements and bouquets. The tall climbing habit makes them excellent for creating vertical interest on trellises, arbors, and fences, where they serve both aesthetic and structural purposes in garden design. Their fragrance adds sensory richness to outdoor spaces, and their ability to attract pollinators makes them valuable companions in gardens focused on supporting bee and butterfly populations.
No timeline data available yet for this variety.
Sow seeds in deep pots 4 to 6 weeks before your last spring frost. Keep temperatures between 55 and 65 degrees Fahrenheit until seeds sprout, which typically occurs within 5 to 30 days. Once seedlings emerge and before their first true leaves unfurl, transfer them to cold conditions outdoors to harden off before transplanting.
Transplant hardened seedlings into the garden after your last spring frost date. Space plants 6 inches apart and provide sturdy trellising for support as they grow toward their full 6-foot height.
Sow seeds directly outdoors 3 to 4 weeks before your last spring frost. Plant seeds 1/2 to 1 inch deep and keep the soil consistently moist until germination.
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“Black Knight is an heirloom sweet pea, part of a botanical tradition stretching back centuries. Sweet peas were beloved in Victorian gardens and developed into hundreds of named varieties through careful seed saving and selection. This particular cultivar represents the preservation work of generations of gardeners who recognized that certain color forms and robust growing habits deserved to be maintained and passed forward. Like all true heirlooms, Black Knight can be saved and replanted year after year, embodying the gardening knowledge of those who came before.”