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.
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.
African Marigolds--Tagetes erecta
Large flowered "African" or "Aztec" Marigolds-- Plants are compact, erect, 12 to 14 inches tall; flowers to 3 1/2 inches across, blooms two to three weeks earlier than tall varieties, most flowers are doubles with flat or ball-like flower heads; colors range from primrose yellow through pumpkin-orange, no bicolors; used primarily as dividers; do not need to be staked as do tall varieties.
Tall--"African" or "Aztec" Marigolds--Large flowers in late summer to fall (short days determine flowering time), orange or yellow; plants attain heights of 3 feet or more and spread 3 feet; space plants 1 foot apart in groups of threes; should be staked or enclosed with wire up to 2 feet in height; used primarily for cutting.
French Marigolds-- Tagetes patula
Large-flowered "French" Marigolds--Used primarily as a divider or bedding plant; medium height (12 to 16 inches and same width) spacing 8 to 12 inches; flowers are large, up to 2 inches in diameter; varieties include flowers which are doubled, large single daisy-like or supercrested.
Dwarf "French" Marigolds--Small plant up to 12 inches; flowers small (1 to 1½ inches across) in colors of yellow, gold or orange; continuous flowering from early summer to late fall, blooms may be crested, tufted, button or single types; some varieties are bicolored, yellow marked with brownish-red; two plantings may be needed as flowering becomes sparse during hot summer "dog days" from planting date.
Triploids (Tagetes erecta x Tagetes patula) hybrid
Triploids-- a cross between "French" and "African" Marigolds; flowers about 2½ inches across and flower well during hot weather; flowers may be bicolored.
Single Marigolds - Tagetes tenuifolia (signata) pumila Single marigolds- simple, daisy-like blooms and long stems; some varieties of merit are Cinnabar, Burgundy, Ripples and Chippendale Daisy.