Zinnia Seeds,
Oklahoma White

Oklahoma White Zinnias can be sown outdoors after the last frost, or started indoors about 4 weeks earlier to extend the blooming season. They perform best when soil temperatures reach around 75 to 80°F. If you’re not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Sow seeds ¼ inch deep, spacing them 9 to 12 inches apart to allow for good airflow, which helps prevent powdery mildew. Oklahoma White zinnias grow to about 30 to 40 inches tall and require spacing for air circulation to keep them healthy. If starting indoors, use biodegradable pots or other means to minimize root disturbance when transplanting​.

These zinnias need regular but moderate watering, allowing the soil to dry slightly between waterings to prevent disease. Fertilizing lightly every 4-6 weeks supports abundant blooms. In hot climates, they tolerate partial shade but will still need plenty of sunlight to thrive.

• Allow the flowerhead containing the seeds to mature and dry on the plant.
• Clip off the flowerhead and place it in a paper bag or other container.
• Working over the top of another clean, opened container, rub the flowerheads between the palms to break them apart.
• The seeds can be separated from the chaff by first screening and then winnowing.
• Store in a cool, dry, dark place over winter.