The humble, common marigold (Tagetes spp) is the sturdy workhorse among annual bedding flowers that provide a steady infusion of color for a single growing season. Available in the sunrise-to-sunset spectrum of luscious gold, amber, orange, cream and maroon-streaked buttery tones, sizes almost as varied as colors range from 6 inches to 4 feet tall and 6 inches to 3 feet wide. Marigolds take about eight weeks from seed to bloom.
The simple-to-handle needle-shaped seeds are successful performers well-suited to both children’s and senior citizen gardening activities. In frost-free areas, you can plant seeds anytime between fall to early spring. In U.S. Department of Agriculture plant hardiness zones prone to snow and freezing temperatures, wait until May or June to plant.
Choose a sunny location for fastest flowering; marigolds do fine in up to 20 percent shade, but take longer to bloom. Use a small garden rake to break up soil, and remove any weeds or rocks. Place seeds 6 inches apart. Cover with 1/4 inch of fine soil. Tamp down lightly, and soak gently so that seeds aren't displaced. Keep evenly moist. Sprouts emerge in days. When leaves form, you can thin or transplant to 8 to 10 inches apart for smaller types or 10 to 12 inches for larger varieties.
Follow the same directions for containers, but use potting soil or soilless potting mix. Regular dirt is too dense.
If your area has a short growing season or you don’t want to wait two months, start seeds indoors six to eight weeks before the area's predicted last scheduled frost. Germinate seeds in starter or potting mix in inexpensive seed-starter trays or peat pellets.
Transfer to 3-inch individual containers of soiless potting mixture when leaves form. You can also pop developed seedlings into shallow window boxes or pretty planters that fit on a sunny sill, snugly tucked away until they can be moved outside when warm weather arrives.
Marigolds require little care beyond watering when first planted, and as needed in extremely hot or drought conditions. Deadheading, gardener lingo for pinching off spent blossoms, encourages flowers to keep forming. Apply water-soluble fertilizer labeled all-purpose or for use on flowering plants at a rate of 1 tablespoon per gallon of water every couple of weeks. Over-fertilizing will result in more greenery than flowers.
In freeze-free USDA zones 9 to 11 long-lasting annual marigolds may masquerade as perennials. A few perennial marigold varieties will last well beyond a single growing season, but these are uncommon in home gardens.