3 Things You Need to Know About Calendula

Calendula can grow to almost two feet tall, and the flowers tend to open with sunny, dry weather and close in cold or moist conditions. They enjoy full sun — or even partial shade in hot summer regions — and average soil. They need a moderate amount of water and if flower production dwindles, you can cut back the plants to promote new blooms.

Calendula will self-sow yearly in many gardens and don't mind crowding. Direct-sow the seeds in early spring or late fall, as they can withstand some frost.

Collect the flower heads on hot, sunny days for the highest resin content, and pick them regularly to prevent the plants from putting their energy into seed production. Once that happens, the rest of the flowers will be smaller.

Choose flowers that are just opening in the morning before noon, and dry calendula quickly after you harvest it. Check the center of the flower for dryness because molding in storage is a problem. Watch for reabsorption of moisture and keep it in complete darkness.

You can use the freshly dried flower heads to make creams, salves, tinctures, and oils, or add the flower heads directly to your bath.

While some research has indicated that anti-inflammatory properties in calendula may help with some skin conditions like diaper rash, take care in applying to your children or yourself.

The National Institutes of Health rates calendula as "likely safe" but talk to an MD if you're concerned.