Tweedia milkweed is a half-hardy vining flower from the Apocynaceae family, prized by gardeners in zones 10-11 for its delicate, sky-blue blooms that attract butterflies and pollinators. This tender perennial grows as a graceful climber, reaching upward with moderate water and partial sun, thriving in neutral to slightly acidic soil. Start seeds indoors 6-8 weeks before your last frost, or direct sow 2-4 weeks before in milder climates, and watch it vine upward with minimal fuss once established.
Partial Sun
Moderate
10-11
?in H x ?in W
—
High
Hover over chart points for details
The soft blue flowers of tweedia milkweed are utterly captivating, appearing on vining stems that climb beautifully when given support. Its half-hardy nature means it thrives as a tender annual or perennial in warm zones, tolerating moderate watering without demanding constant attention. Butterflies adore it, making it a living magnet for pollinators in gardens where it can sprawl or climb.
Tweedia milkweed is grown ornamentally for its striking blue flowers and vining habit, making it an excellent choice for trellises, arbors, and garden structures where its climbing stems can be trained. Its butterfly-attracting properties make it valuable in pollinator gardens and naturalized landscapes.
No timeline data available yet for this variety.
Start seeds indoors 6-8 weeks before your average last frost date. Maintain a soil temperature of 70-80°F for germination. Sow seeds at a depth of 1/4 inch. When seedlings develop 3 sets of leaves, thin to one plant every 12-24 inches to prevent overcrowding.
Transplant hardened-off seedlings outdoors 6-8 weeks before your average last frost date, once soil has warmed and frost risk has passed. Space plants 12 inches apart with 18 inches between rows.
In mild climates, direct sow 2-4 weeks before your average last frost date. For fall sowing in mild regions, seeds will germinate in spring.
Prune vining stems as needed to shape growth and encourage fuller, bushier development. Remove any leggy or weak growth to redirect energy toward flowering. Light pruning encourages branching and more abundant blooms.
Enter your ZIP code to see a personalized growing calendar for this plant.