Calendula officinalis, commonly known as Pot Marigold, is a widely cultivated annual or short-lived perennial plant. This cheerful herb is part of the daisy family, Asteraceae, and is characterized by bright, daisy-like flowers that range from pale yellow to deep orange. Originating likely from southern Europe, the plant has been naturalized across the globe due to its long history of cultivation. The genus name, Calendula, derives from the Latin word “kalendae,” referring to the first day of the month, suggesting its ability to bloom almost year-round in mild climates.
Selecting the Best Cultivar for Your Needs
Before purchasing, understand that not all calendula varieties offer the same concentration of beneficial compounds. Many commercially available types are bred primarily for aesthetic appeal, often lacking the high resin content desired for medicinal and culinary applications. The compounds responsible for the plant’s anti-inflammatory and wound-healing properties, such as triterpenoid saponins and carotenoids, are concentrated in this sticky resin.
For those intending to harvest flowers for salves, infusions, or food coloring, selecting a high-resin cultivar is recommended. Varieties like ‘Resina’ and ‘Erfurter Orangefarbige’ are known among herbalists for their superior resin production. Deep orange varieties also tend to contain a higher concentration of powerful carotenoid pigments than paler yellow types.
Sourcing Methods for Plants and Seeds
The process of acquiring calendula involves choosing between purchasing seeds or pre-started plants (transplants). Starting from seed is the most cost-effective method and provides access to a wider selection of specialized cultivars, including high-resin varieties. Seeds are widely available from specialized online seed banks, which often carry organic and heirloom options.
Buying transplants offers the advantage of immediate planting and quicker blooming, bypassing the initial germination stage. Local independent nurseries are often the best source for quality transplants suited to the regional climate. While big box stores sell calendula, these are frequently ornamental varieties, so buyers should verify the specific cultivar name if seeking a plant for herbal use.
Cultivating Calendula After Purchase
Once you have acquired your plants or seeds, providing the right environment is important for maximizing flower production. Calendula thrives best in full sun, requiring at least six hours of direct light daily, though it tolerates partial shade in hotter climates. It requires well-draining soil to prevent root rot, and amendments like compost can improve overall health.
Watering should be consistent until the plants are established. Once mature, calendula is relatively drought-tolerant and should be watered deeply only when the top inch of soil feels dry. Continuous flower production is maintained by deadheading, which involves removing spent flower heads to signal the plant to produce more blooms instead of seeds. Occasionally, pests like aphids or whiteflies may appear, but a gentle spray of water or insecticidal soap can manage small infestations.
Preparing the Harvest for Topical and Culinary Use
Harvest the flowers when they are fully open, ideally during the mid-morning after the dew has evaporated, when resin and volatile oils are most concentrated. Use clean scissors or pinch the flower head off at the base; frequent harvesting encourages more blooms. Harvest the entire flower head, including the green base, as this part contains a significant concentration of beneficial compounds.
To preserve the harvest, the flower heads must be thoroughly dried to prevent mold and retain potency. Spread the flowers in a single layer on screens or trays in a warm, dark, and well-ventilated area, away from direct sunlight. Because of the thick centers, the drying process can take up to two to three weeks, and they must be completely brittle before storing them in an airtight container.
Dried calendula is ready for use in oil infusions to create topical salves and creams. The petals can also be separated and used as an edible garnish or saffron substitute to add color to rice and salads.