Mexican Marigold Tagetes erecta

Tagetes erecta, or African Marigold, is a frequently cultivated, tender, flowering, herbaceous annual or houseplant known for its large flowerheads. Tall varieties may need staking, and spent flowers should be promptly deadheaded, as flower heads are heavy and can cause stems to snap.  Triploid F1 hybrids (T. erecta x T. patula) combine the large flowers of the African marigold with the more compact size of the French marigold into vigorous plants featuring 2 to 3 inch diameter flowers on stems rising 10 to 18 inches tall. These triploids seem unaffected by high summer heat and generally bloom throughout the summer. The genus, Tagetes, is named for an Etruscan deity, Tages and the specific epithet means erect or upright.

Despite its name, the plant is native to Mexico and uncultivated African Marigolds can be found in pine-oak forests and as escapees from a garden growing along the sides of roads. African Marigold tolerates clay and dry soil but prefers evenly moist, well-drained soil. It does well in full sun, which encourages blooms, but appreciates some light afternoon shade; however, it does not do well in full shade.  Leaves and flowers are fragrant when brushed or crushed. You can pinch back young plants to promote bushy growth. 

It will grow best from seed that you can start indoors 6 to 8 weeks before last frost date and is also available as plants in six packs from local nurseries. Set plants out after last frost date. Plant taller varieties deep is sites protected from strong wind or heavy rain to minimize the need for stem support. Promptly deadhead spent flowers.

Diseases, Insects and Other Plant Problems: 

Possible diseases include botrytis, leaf spot, phytopthora, powdery mildew, and other rots. Potential insects include Thrips, slugs and spider mites. Some cultivars have shown good to excellent resistance to phytophthora and fusarium wilt while other cultivars show poor resistance to abiotic disorder and fusarium wilt. See Phytophthora Root and Crown Rot in the Landscape.

 VIDEO Created by Elisabeth Meyer for "Annuals, Perennials, Vines, and Groundcovers" a plant identification course offered in partnership with Longwood Gardens.