Ferry-Morse Sunflower Mammoth seeds promise an impressive addition to your garden. These annual flowers, known for their large size and bold presence, thrive in full sun, reaching towering heights and producing massive blooms. Mammoth Sunflower is an easy-to-grow summer annual and the state flower of Kansas. Stately sunflowers with enormous heads, more than 1 foot across, provide spectacular beauty first, then seeds for roasting or birdfeed. With their cheerful yellow petals and dark centers, Mammoth sunflowers are a favorite of pollinators and gardeners alike. Plant in well-drained soil and watch as these majestic flowers bring joy and beauty to your outdoor space throughout the growing season. After all the danger of frost, sow Ferry-Morse sunflower seeds in open ground well exposed. Cover with 1 inch of soil. When plants are 4 inches tall and thin. Needs lots of water. Light Needs: Full Sun Plant Lifecycle: Annual Seed Depth: 1″ Seed Spacing: 18-24″ Days to Germination: 14 Days to Maturity: 75-90 Hardiness Zones: 2 – 11