Ranuculus asiaticus are not winter hardy in areas colder than Zone 8. They should be planted shortly before the last spring frost and will go dormant with the summer heat. It is important to know that winter storage of these bulbs is difficult at best.
Preparation for winter storage:
When the foliage yellows and begins to dry out, it is the time to dig the ranunculus tubers from the ground. After you lift the tubers, allow the bulbs to dry out for several days before putting the bulbs in storage. You could even place the tubers in the sun for a couple hours. The key is to let the surface dry so that mold doesn't form on the tubers.
Store the tubers packed in a dry media (peat moss) in a cool, dry, well-ventilated place that is 50 to 55 degrees F. Be sure to check periodically for mold, and maintain low humidity in the storage facility.
