Marigolds (Tagetes sp.)
Scientific Name: Tagetes sp.
Origin: South America-Argentina and New Mexico
Classification: Annual, herb
Use: Bedding plants, pot culture, edging, cut flowers
Height: 6 inches to 4 feet
Spread: 6 inches to 3 feet
Stems (Bark): Herbaceous
Flowers: Orange, yellow, mixed, red, cream and maroon; rounded or flat heads
Foliage: Lacy, feather-like, finely dissected, opposite, often pungent odor
Texture: Medium to fine
Growth Rate: Rapid
Soil Requirements: Good garden loam, moist, well drained
Maintenance: Keep soil moist but not wet. Remove spent flower heads for continuous flowering
Situation: Sun; flowering delayed if planted in shady areas
Insects & Diseases: Spider mites, spittle bug, aster yellows, wilt
Remarks: Propagate from seed sown indoors in March, April, or direct seed outdoors in May after danger of frost has passed.
Marigolds require approximately 45 to 50 days to flower after seeding, therefore seeding indoors should be done in late March or early April. The plants should be ready for planting outdoors after the danger of frost has passed, about May 15.
Seed may be planted in seedbeds, cold-frames, flats, clay pots, or peat pots.
Pulverize the soil. Place the seed on the surface or in furrows and cover with 1/4 inch of perlite or vermiculite.
Keep the soil moist and warm. The seed will germinate within a few days.
When true leaves appear, the individual plants may be transplanted into individual 3-inch containers. Shade for a few days until the plants become established.
Give the plants full sun.
Plants will be ready to plant in the garden after the danger of frost has passed. Marigolds may be seeded directly into the garden after the danger of frost has passed. Follow the directions above as to preparing soil and seed depth. Seedlings may be thinned if necessary.
Other Varieties: There are many varieties of Marigolds and new ones are introduced each year. Various references group the species and varieties in many different ways, such as by size, (large, semi-dwarf, dwarf) or flower shape, such as chrysanthemums or pompon types, peony types and singles. However, for simplification, here, Marigolds are divided into four basic species: African Marigolds--Tagetes erecta; French Marigolds--Tagetes patula; Triploids--a hybrid (Tagetes erecta x Tagetes patula); Single Marigolds--Tagetes tenuifolia (signata) pumila. Within each of these species there are many hybrids producing variations in color and size.
Information obtained from http://www.wvu.edu/~agexten/hortcult/flowers/marigold.htm