If you have a short growing season and want healthy zinnia plants as soon as possible, start seeds indoors at least a month before your last frost date. Sow zinnia seeds into a peat pot or other ...

While you can start their seeds indoors and then plant them out a few weeks after your last frost, zinnias are also great ...

Looking to plant seed directly in the garden? These guys can be started indoors for six to eight weeks or directly in the garden soil: marigolds, zinnia, sweet peas, sunflowers, cosmos ...