Common Names: Pot Marigold, English Marigold, Field Marigold.
Life Cycle: Hardy annual.
Height: 12 to 30 Inches (30 to 75 cm).
Native: Mediterranean, Middle East.
Growing Region: Zones 2 to 10.
Flowers: Spring through to autumn; may also bloom in winter in warm frost free areas if sown in the autumn.
Flower Details: Yellow, red, orange, cream. Daisy-like ray and disc florets.
Foliage: Bright green. Slightly hairy. Ovate.
Sow Outside: 1/4 inch (6mm). Early spring and/or summer (mild climates) or towards the end of autumn (in warm climates). Spacing. 6 to 24 inches (15 to 60 cm).
Sow Inside: Germination time: one to two weeks in the dark. Temperature 70°F (21°C). Seven or eight weeks in advance. Transplant outdoors following the last frost.
Requirements: Full sunlight or light shade. Soil pH 5.5 to 7. Average soils. Occasional feed. Regular watering; avoid getting water on the leaves. Pinch tips. Deadhead. Bring plants indoors for the winter in frosty areas; potting. Propagate: cuttings in the summer.
references : http://www.gardenershq.com/Calendula-pot-marigold.php