Annual
Calendula (Pot Marigold)
Calendula officinalis · Asteraceae
Also called: Pot Marigold, English Marigold, Common Marigold
Calendula (Pot Marigold) (Calendula officinalis) is a moderate-water annual well suited to Tucson and the low desert. It grows to 12-24 in tall by 12-18 in wide in full sun in winter, with a fast growth rate.
Calendula (Pot Marigold) at a glance
- Water use
- Moderate (established)
- Sun
- Full sun in winter; appreciates light afternoon shade as spring temperatures climb.
- Mature size
- 12-24 in tall by 12-18 in wide
- Growth rate
- Fast
- Bloom
- Yellow, gold, orange, apricot, cream, December through May in the low desert (winter/early-spring bloomer)
- Cold hardiness
- Frost-tolerant to about the upper 20s F; hardy through typical Tucson winters but declines in heat above ~85-90 F.
- Soil
- Well-drained loam to sandy soil amended with compost; tolerates a range of pH but prefers neutral to slightly alkaline.
- Native range
- Mediterranean / Southern Europe (garden origin uncertain; long in cultivation)
- Best used as
- Winter color beds, Borders, Containers, Cut flowers, Edible/culinary petals, Pollinator plantings
- Wildlife
- Attracts bees, butterflies, and other pollinators; reputed to help repel some garden pests.
- Toxicity
- Generally considered non-toxic and even edible (petals used as a saffron substitute and in salads); safe around kids and pets. Can cause mild contact dermatitis in sensitive individuals.
How to grow Calendula (Pot Marigold) in Tucson & the low desert
Watering
Keep soil consistently moist but not soggy; water roughly every 3-5 days, more often in warm, dry, or windy spells. A cool-season annual: set out transplants or sow seed Sept 15-Nov in Tucson for blooms Dec-May.
Fertilizer & nutrients
Work compost into the bed at planting; feed every 2-4 weeks with a balanced water-soluble fertilizer or a light all-purpose granular. Over-feeding produces foliage at the expense of flowers.
Pruning & care
Deadhead spent flowers regularly to extend bloom; pinch young plants once to encourage branching. Pull and compost when plants decline in late spring heat.
Notes
A reliable, easy cool-season annual for Tucson. Plant Sept 15-Nov for winter-into-spring color; performs best before the heat arrives. Self-sows readily. Petals are edible and have a long herbal/medicinal history (calendula salves).
Sources: University of Arizona Cooperative Extension (Pima County Master Gardeners) cool-season annual guidance; Arizona low-desert planting calendars (growinginthegarden.com, greenthingsaz.com); Missouri Botanical Garden Plant Finder