How to plant marigold seeds indoors Fill small pots with a seed starting mix. Biodegradable pots in a plastic seed starting flat are ideal. Sow three to four seeds in each pot, about 1/4-inch deep ...

Zinnia Photo Credits: Unsplash Sow zinnia seeds deep into well-drained soil and keep watering the soil twice a day. Zinnia seeds grow into beautiful plants in summers and bloom in different colours.

Signet marigolds (Tagetes tenuifolia): This variety has petite single-petaled flowers, though different cultivars may vary in height, from eight inches to two feet tall.