These are some of the most popular annual flowers on earth. The marigold group called "Crackerjack Mix" has decorated millions of gardens for decades. These are the big ones—bright, ball-shaped flowers in yellow and orange on sturdy plants 2–3 feet tall. A blend of bright shades of orange, gold, yellow, and primrose. Huge flowers with gracefully overlapping petals bloom from midsummer to first frost.
After all danger of frost has passed, sow seeds in a sunny area of the garden on open ground and leave them well exposed. Cover with one quarter inch of soil and water well. Fertilize throughout the season as needed.
For earlier bloom, starts indoors in flats about six to eight weeks before the last frost. When plants are about 2 inches tall, thin or harden off marigold plants before transplanting to the garden.
Harvest marigold seeds when petals are dry and the base of each bloom is turning brown.
Set a paper towel on a flat surface. Then, holding the base of each bloom (leave marigolds in the ground), pull off and discard the petals and leaves. You'll see long rods inside the seed heads called achenes. Each achene has a seed attached to it. Set the blooms on your paper towel.
Marigold seeds are attached to the achenes (seed is the darker end). Pick up each bloom and pull seeds away from the base. Separate seeds and spread them on a paper towel. Place paper towel out of direct sunlight and allow seeds to air dry, uncovered, for about one week. Store in a cool, dark place for up to five years.