In the winter, tobacco budworms take shelter below ground, where they hibernate as pupae until spring arrives. However, if exposed to extremely cold temperatures (below 20° F), the overwintering pupae are unlikely to survive. Budworms can overwinter happily in the soil of potted plants that were outdoors during the summer and then moved indoors to a warm location for the winter. They also may be active year-round in greenhouse-grown plants.