Annual
French / African Marigold
Tagetes erecta · Asteraceae
Also called: African marigold, American marigold, Aztec marigold, Big marigold
French / African Marigold (Tagetes erecta) is a low-water annual well suited to Tucson and the low desert. It's a fast-growing annual.
French / African Marigold at a glance
- Water use
- Low (established)
- Sun
- Full sun for best flowering; light afternoon shade is tolerated and helpful in the hottest part of summer.
- Mature size
- Tall types (T. erecta) reach 1-3+ ft tall; 'French marigold' dwarf forms (often T. patula or hybrids) are 6-12 in
- Growth rate
- Fast
- Bloom
- Yellow, gold, orange, and creamy white (large, often double pompon flowers), Spring into early summer (peaks through about June), then again in fall; flowering pauses in the most intense midsummer heat.
- Cold hardiness
- Frost-tender; damaged/killed by frost. Tolerates heat but flowering declines once temperatures regularly exceed ~100F.
- Soil
- Moderately fertile, well-drained soil amended with compost; tolerant of alkaline desert soil.
- Native range
- Mexico and Central America (despite the 'African' common name); grown as a cool-to-warm-season annual in Tucson
- Best used as
- Color beds and borders, Containers, Cut flowers, Companion planting in vegetable gardens (often used to deter pests/nematodes), Cool-season/fall color
- Wildlife
- Attracts bees and butterflies; the strong scent tends to deter rabbits and some insect pests. Roots are reputed to suppress soil nematodes.
- Toxicity
- Generally considered non-toxic to pets and people; foliage sap can cause mild skin/contact dermatitis in sensitive individuals. (Note: 'African marigold' the name sometimes confused with toxic Tagetes minuta.)
How to grow French / African Marigold in Tucson & the low desert
Watering
Plant in spring (March-April) for late-spring/early-summer bloom, or in late summer/fall (September) for fall color, which often performs better than peak summer. Water deeply 2-3 times per week; keep foliage dry and water at the base to limit fungal problems and spider mites in heat.
Fertilizer & nutrients
Light to moderate feeder. Amend with compost and apply a balanced fertilizer at planting; feed lightly every 4-6 weeks. Excess nitrogen produces foliage and fewer blooms.
Pruning & care
Deadhead spent flowers regularly to keep plants blooming; pinch young plants to encourage branching and a fuller habit.
Notes
Botanical name is correct. In Tucson, marigolds bloom reliably mainly through June, then struggle in peak summer heat - plan them as spring and especially fall annuals rather than midsummer color. Watch for spider mites in hot, dry, dusty conditions. The true 'French marigold' is usually Tagetes patula; T. erecta is the African/American/Aztec marigold.
Sources: University of Arizona Cooperative Extension - Pima County Monthly Gardening Guides; North Carolina Extension Gardener Plant Toolbox - Tagetes erecta; Missouri Botanical Garden Plant Finder - Tagetes erecta