The optimal period for sowing these annual flower seeds hinges significantly on local climate and the last expected frost date. Zinnia seeds germinate best in warm soil, typically requiring temperatures consistently above 70F (21C). Planting too early, before the ground has adequately warmed, can lead to poor germination rates and seedling failure.
Proper timing is critical for robust plant development and abundant blooms throughout the summer season. Starting seeds at the appropriate time ensures seedlings emerge in favorable conditions, leading to healthier plants more resistant to pests and diseases. Historically, gardeners have relied on their understanding of local weather patterns and soil conditions to determine the ideal sowing window.
