75 - 90 days. Our Zinnia varieties are carefully selected for vibrant color, sturdy stems, vigor, yield, quality, disease resistance, and long vase life. As low as $19.95. Ferry-Morse Ferry-Morse 800 Milligram(s) Zinnia Giant Cactus Mixed Colors Flower Seeds (Seed Packet) Item # 2772259 Model # 461425.158.905912 Get Pricing and Availability With a bulk mix of California Giant zinnia seeds, it's possible to see all the colors of this beautiful and meaningful flower. The “king of summer annuals” California Giant Mix seeds are the largest variety of Zinnias ever, growing 4' tall and bursting with spectacular 5 – 6” semi-double flowers. Harvest often for continuous blooms. Giant Cactus Zinnia Seed Mix Zinnia Giant Cactus Mix Zinnia elegans Giant Cactus Mix. Annual. Sow Right Seeds California Giant Zinnia Seeds - Full Instructions for Planting, Beautiful to Plant in Your Flower Garden; Non-GMO Heirloom Seeds; Wonderful Gardening Gifts (2) 4.3 out of 5 stars 106 $7.99 HOW TO GROW. We are pleased to offer a wide range of colors, shapes, and sizes to choose from, including giant zinnias with blooms up to 6" in diameter. Sowing: Direct sow in spring; this California Giant zinnia flower seed mix germinates best in warm soil. Giant Cactus Zinnias are a highly sought-after variety and this mixture will delight with unique, needle-like petals on large flowers that can reach 4-5" across! Per 1/4 Pound. Zinnia elegans.