An annual plant also known as American marigold, African marigold (Tagetes erecta) produces huge round blooms atop sturdy stems adorned by bright green, ferny foliage. One of the largest members of the marigold family, African marigold attains a height of 2 to 3 feet at maturity. These drought-tolerant, sun-loving plants bloom in a variety of bright colors, including orange, yellow, rusty-red, mahogany and gold. The impressive flowers measure as much as 5 inches in diameter.
Prepare the soil in a planting bed where the African marigolds will receive full sunlight. Spade the soil to a depth of 6 to 10 inches, then dig in 2 to 3 inches of organic matter such as pine bark, compost or leaf mold
Dig a hole in the prepared area with a trowel or shovel, then plant the African marigold slightly deeper than it was planted in the nursery container. Fill in around the roots with soil, then water deeply. Allow 18 inches between each plant.
Sprinkle 1 teaspoon of dry 10-20-10 fertilizer around the plant. A small amount of fertilizer is sufficient, and more can result in lush, green plants with no blooms.
Water African marigolds as needed to keep the soil evenly moist during the first 10 to 12 days. Thereafter, water when the soil is almost completely dry -- usually once every week. Water to a depth of 8 to 10 inches, using a garden hose or soaker hose at the base of the plant to keep the foliage and blooms dry. Soggy soil and humid conditions can cause the plant to rot.
Pinch the growing tips of newly planted marigolds once or twice to force branching and create a full, bushy plant. Pinch the tip and the stem down to the next branch, leaf or bud.
Snip blossoms from the plant as soon as they wilt. Otherwise, the plant sets seed and flowering decreases rapidly.