Grow Mixed Hydrangea Flower from seed for colorful beds, borders, containers, or cut flower arrangements. Why gardeners choose it Adds garden color with an easy seed-starting option Useful for beds, borders, containers, or mixed plantings A practical choice for seasonal flower displays Pairs well with other annual and perennial garden favorites Good for gardeners building a more colorful outdoor space Planting notesSow Mixed Hydrangea Flower in spring where it can receive partial shade. Keep the seedbed evenly moist until germination, usually 14-30 days. Grow plants to about 3-6 ft. and plan for blooms in about 2nd year. Best suited to USDA zones 3A-9A. Adjust sowing time for your local frost dates and summer heat. Use local planting dates, weather, and soil conditions to fine-tune sowing time and care.