Last winter was very warm for the most part and trees start breaking buds in mid February. As this was my first winter in bonsai, I thought it best to take the trees that were breaking buds out of the greenhouse and get them in full sun. I think this was the wrong thing to do now, but I am not sure what the best practice is for determining when to move them out full time. In my area the last freeze is always anticipated no later than first week of April. Would the best thing to do be to wait until then even if buds are breaking? Or would there be some adverse affect from leaving a leafing tree in a greenhouse potentially several weeks?
I know that moving trees from greenhouse to outside in spring must be done with care, but I’d love to hear from people who live in cold climates what their experience has been.
One way to avoid this issue could be to overwinter your trees in a darker, sheltered space. I keep all of my small to medium sized trees, conifers and deciduous, under the bench and covered with poly sheeting. Some of my trees, particularly my crab apples and alders, start to push buds up to a month before I feel comfortable putting them on the bench, but since it is pretty dark and cool (at least relative to a greenhouse) underneath they don’t really start to grow until they are out in the sun. It seems like a pretty smooth transition. Plus it would save you valuable winter greenhouse space!
I live in central MD, zone 7a. Not too cold most of the time but we do have periods of very cold weather.
Like brad I build little plastic shelters on benches and even picnic tables. However I keep the sides open all the time unless it gets very cold or there is a very drying wind. I close it up if it goes below 25 F. Therefore there is constant air circulation. However I have the pots buried in mulch.
(Even if there’s wind I still keep plastic open on leeward side as long as temps are not below 25 F.)