Sweet Six­teen

Sow Cosmos: Sow seeds in cell packs or flats, press into soil and lightly cover, 4 to 6 weeks before transplanting into the garden. When kept at 70 to 85° F., germination is in 7 to 21 days. Can direct sow cosmos seeds into prepared seed beds, up to ⅛ inch deep, after all danger of frost has passed. Sow 4-6 seeds per foot. Thin seedlings to 12 to 15 inches apart.

Grow Cosmos: Full sun. Best flower production is in soils of average fertility with moderate water. Cosmos tolerate heat, drought, and poor soil. Remove spent blooms to promote additional flowers. Cosmos will usually self-sow if some spent blossoms are kept on plants. Cut flowers typically last 5 to 9 days when blooms are cut as petals unfold. Flowers fully open in vase. Cosmos attract birds, bees and butterflies and are rarely bothered by pests or disease.

Dig Deeper: Tip to bring your cosmos plants into bloom up to 3 weeks earlier when growing under fluorescent lights: once seedlings have emerged provide 11 hours per day of artificial light. Keep seedlings in complete darkness for the remaining 13 hours. After 2 weeks, keep the lights on for 14 or more hours per day.

U.S. Shipping Rates

Free shipping on U.S. orders over $60.00.
Free priority shipping on U.S. orders over $150.00.

Standard U.S. shipping is $5.99.
Priority U.S. shipping is $9.99.

International Shipping Rates

Shipping to Canada is $13.99.
International shipping to all other countries is $15.99.

We guarantee all the seeds we sell for one full year from the date of purchase. If you are unsatisfied with any seeds purchased from Swallowtail Garden Seeds, we will issue a refund. For customers in the U.S., we can send one-time replacements or issue a refund.