With potting season coming up, when is the best times to repot Shimpaku juniper, Mountain hemlocks and Mugo pines in the Seattle area.

From Dave D.: “In general, repotting for temperate species should be done before or just as new growth (such as bud swelling) commences. As mountain hemlocks and Mugo pines are both high elevation temperate species that maintain root growth throughout most of our winter, they can be repotted here starting in February, provided only that they are offered protection in the event of a hard or extended freeze. Shimpaku are a form of Chinese juniper native to both mountain environments and subtropical lowlands. I usually wait until mid-march if the tree will not recover in a protected space such as a cool greenhouse, but shimpaku can also be safely repotted far into spring. Some growers even repot in summer, although I have no experience with that and would not recommend it, now that our summers are becoming increasingly hot and dry.”