Mediterranean trees - winter in a cold climate

How do folks overwinter Mediterranean and similar trees/shrubs that can often handle some frost in cold weather areas that would kill them outside? I have have had mixed results with some of mine. Here are my results, but would like to get additional feedback and expand the list for others.

  • Bougainvillea - inside in a sunny window. Can tolerate a light frost.
  • Pomegranate - inside in a sunny window. Have also kept in the cool (just above freezing) greenhouse for a few weeks before coming inside.
  • Olive - kept it inside the first year and it did well. Does it need some dormancy - cool greenhouse for a few weeks?
  • Rosemary - does OK over winter inside and then slowly dies during the spring and summer (twice).
  • Coast live oak - cool greenhouse seems to work, but mine are seedlings.

Please add your experience and other species. - Marty


In Portland, I’ve kept most of my Mediterranean trees on the ground, close to the house grouped with all my other trees and then covered with agribon row covers (fabric not plastic). This includes Coast Live Oak and Pomegranate. I brought my olive in last year but I’m not sure I’ll do that again this year, I’m going to try leaving it out.

I don’t remember Portland getting super cold last year, maybe only down to about ~20F, and only momentarily and back above freezing most days.

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