Calendula vs Marigold: Size

• Marigolds vary from low-growing, dwarf varieties that do not grow more than 6 in. tall (15 cm) to upright varieties that easily reach 4 ft. (120 cm). 
• Calendula plants usually grow up to 12-24 in. tall (30-60 cm) and rarely beyond 24 in.

Calendula vs Marigold: Flowers

• Marigold flowers can be single, double, crested, or pompon-like. They are available in shades of orange, yellow, red, gold, white, and any combination of those colors.
• Calendula flowers have a daisy-like shape with brown to yellow central disks. They are typically bright orange or yellow but some white and bi-colored cultivars have been developed.

Calendula vs. Marigold: Leaves

• Marigolds have divided, fern-like leaves that are serrated, smooth, and soft to the touch.
• Calendula plants have sticky, hairy, lance-shaped leaves.

Calendula vs Marigold: Seeds

• Marigold seeds are straight black seeds with white tips that look like little porcupine quills.
• Calendula seeds are brown, curved in a C shape and look like curly worms.

Calendula vs Marigold: Scent

• Marigolds have a strong, pungent scent that repels pests such as deer, rabbits, or mosquitoes since they find the odor offensive.
• Calendula flowers and leaves have a more pleasant aroma compared to Marigolds.
• If you ever find yourself confused between Marigold and Calendula, give the flower head a sniff.

Calendula vs Marigold: Toxicity

• Most Marigolds are inedible and toxic. There are, however, a few exceptions. The flowers of Tagetes tenuifolia (Signet Marigold) have a pleasant lemon scent and are edible. Tagetes lucida (Mexican Tarragon is often used as a substitute for tarragon. Tagetes minuta (Wild Marigold) is used as a culinary herb in Peru, Ecuador, and parts of Chile and Bolivia.
• Calendula leaves and petals are edible. The leaves are often added to salads, and the fresh petals can be used as a garnish or seasoning. 

Calendula vs. Marigold: Companion Planting

• Marigolds produce a substance that suppresses nematodes (microscopic worms that attack the roots of plants), making them suitable for growing in vegetable gardens.
• Calendula is often grown as a trap crop, trapping pests such as aphids, whiteflies, and thrips by exuding a sticky sap (resin) that they find more appealing and delicious than nearby vegetable crops.

Calendula vs Marigold: Medicinal Uses

• Calendula flowers can be used as a medicinal herb as they possess wound-healing and local anti-inflammatory properties.
• Marigolds have been traditionally used for stomach problems, coughs, colds, and sore eyes. But there is no scientific evidence to support these uses.