Gently pull apart petals and place them in a dehydrator.
Set at 90°F for 12 hours.
After 12 hours, rub them between your fingers to feel for any moisture. If they are not completely dried out, continue to dehydrate until they are.
Store in a mason jar until ready to make tea.
To make tea:
Bring one cup of water to a boil.
Add one tablespoon of dried petals to a tea ball and steep for 10-12 minutes.
Notes
You may let calendula petals air-dry in the house or outside (on a non-windy day!), but it will take much longer. See this post for step-by-step directions.