Freezing Temperature

Bonsai are kept outdoors and on occasion some can be brought indoors for about three days. Leave them outdoors as much as possible. They need to go through their seasonal changes (dormancy). Pines can easily be killed by being brought indoors ever. Learn the Hardiness Zones for each type of tree that you want to grow. Some trees are hardy to 20 degrees F (Pines, Maples, Junipers). Others are less hardy only to freezing (Serissa, Carissa, Sweet plum). Some tender tropical trees need to be kept above 45 degrees F. Azaleas are hardy to only 25 degrees F. Shield bonsai from strong winter winds that dry out the foliage and twigs. Because bonsai are planted in shallow containers the roots can freeze faster than they would if planted in the ground. Also protect the pots. Freezing can cause pots to crack. Freezing and thawing can cause glazed pots to shatter.