If I trim back my large, cold weather damaged, rosemary bushes will they come back this spring?
Jackson County Oregon
It's a sad comment that not all Mediterranean plants are frost-hardy in our so-called "Mediterranean" climate. Rosemary, unfortunately, has many cultivars which are not hardy below 20 degrees F. The tall varieties tend to do better than the prostrate ones. You do not identify the type of your plants, but the following information.should give you some guidance in trying to save them. First, do nothing yet! Our frost seaon is not over: the median date of the last frost in spring in Medford is April 29-- if you are in Ashland or the Aplegate, or located at an altiitude above 2000 feet, it will be later. When you do cut back your plants, you must cut above bare wood into a branch with, hopefully, green leaves. Any branch that has no remaining live leaves may not be salvage worthy. You can scrape the bark with a knife to see if there is green wood in the branch. If none, that branch is dead and should be removed at the base. Rosemary is like lavender; if you cut into a branch below leaf growth, no new growth will form on the "bare" wood. Salvaged plants should be given moderate water until full leafy growth resumes. Do not fertilize rosemary as you do not want lush, soft growth that will be prey to future damage. Rosemary likes hot, more or less dry conditions. Keep healthy plants shapely by pinching back new growth and, if necessary, clipping back up to a third of a branch.Good luck saving your plants.