Tagetes erecta aka Marigold

Tagetes erecta is an annual in the daisy family. Names include African marigold, Aztec marigold, and Mexican marigold. Despite its African name, it comes from Mexico and Guatemala. It grows in the pine-oak forest zone of that region. Plants that escape gardens also grow beside roads in the USA. Aztecs gathered its flowers for rites and decoration. Gardeners now grow it for beds and cut flowers.

Plants form upright, bushy clumps with green stems. Most reach 1–4 feet (0.3–1.2 metres) tall in gardens. The RHS gives an upper height of 4.9 feet (1.5 metres). Spread reaches about 1–2 feet (0.3–0.6 metres). The stems have lines or ridges and may become slightly woody. Their bark has resin channels that release scent when squeezed. Green, pinnate leaves have narrow leaflets with toothed edges. Lower leaves grow in pairs; upper leaves alternate along stems. Leaves and flowers give off scent when rubbed or crushed.

Large flower heads appear from early summer into autumn. Double blooms come in yellow, orange, cream, and white. Other shades include bronze and dark red-brown, with some two-tone flowers. Heads span about 0.16–0.5 feet (0.05–0.15 metres) across. Butterflies and hummingbirds visit the flowers. Small black achenes follow flowering. The long bloom season suits borders, containers, and mass plantings. Deer seldom damage the plants.

Full sun helps the plant produce plenty of flowers. Light shade in the afternoon can suit it, but deep shade does not. It prefers soil that stays evenly moist and drains well. It tolerates clay and dry soil as well. The RHS lists clay, loam, and sand across the pH range. Sow seeds indoors six to eight weeks before the last frost. Plant outdoors once the risk of frost has passed. The RHS rates it H2; it cannot survive freezing. Tall stems may need stakes against wind and heavy rain. Remove old flower heads to extend bloom and reduce stem breakage.

Thrips, slugs, and spider mites can cause trouble. Diseases include botrytis, leaf spot, powdery mildew, and root rots. Flowers supply a yellow dye used to colour food. PFAF also records eating the fresh flower receptacle. It lists folk uses for gut and skin complaints. These records do not establish medical safety or benefit. Sap can cause a rash despite reports of edible uses. Sunlight after sap touches broken skin can cause burning and blisters. Flower scent may irritate the nose and eyes.