Whether you start zinnia seeds outdoors or indoors will ... powdery mildew if their leaves stay wet. Add fertilizer: Working compost into the soil before planting helps zinnias grow better.

And since they are one of the best fast-growing flower seeds around ... a balanced fertilizer every 4-6 weeks during the growing season. She also adds that taller zinnia varieties may benefit ...

These annual flowers grow quickly from seed, don’t mind the heat, and tolerate most types of soil. Zinnias also are ... Native to North and South America, zinnia flowers come in every shape ...