How Do You Overwinter Your Bonsai?

The bigger, more cold hardy trees stay out on the raised concrete patio, packed together and mulched.


The smaller, or more refined trees maples are kept in my unheated workshop. The grow lamps are on for a few weeks at either end of their stay in the room to extend the growing season, but get turned off once I can get temps below 40 F in there.

Dav4 said:

The bigger, more cold hardy trees stay out on the raised concrete patio, packed together and mulched.
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The smaller, or more refined trees maples are kept in my unheated workshop. The grow lamps are on for a few weeks at either end of their stay in the room to extend the growing season, but get turned off once I can get temps below 40 F in there.
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very nice setup

I’ve got a combination of everything, so definitely have to do some rearranging for the winter months to accommodate all of them. We may only see a few days below freezing (28-32F) but we will have 3 months with temperatures between 32-55F. The tropicals go in a portable green house (3’ x 6’ x 6’). I only have about 10-15 trees/plants that need protection below 55F. I will locate it in a sunny area and only close it up when there will be a drop below 55. About half of my collection are good for my area and either stay in the ground or in wind protected areas. None of them need high amounts of winter chill for dormancy

My trees I have to give extra care for are the more northern trees that need a cold winter to thrive well. Since we only get about 200-500 winter chill hours, I have to manually produce good chill time for them. This includes my Japanese Maples, Kwanzan Cherry trees and a few other deciduous trees that want 1000 hours of chill time or more for the dormancy period. I defoliate them around the first of December and put them in garage refrigerators which will keep the temp between 32-45F. I check them every two weeks to monitor their moisture level and water if necessary. These will come back outside around the first week of March. Takes about a week and they explode in new growth. It took me a few years to realize how important that winter rest (chill time) was for them. Lost a few to a slow death because they weren’t getting proper winter sleep. If you love the JMs and Kwanzan Cherry trees and live in tropical areas, it’s doable.

I only have one tropical tree, a fukien tea. he will come inside here in about another week or two, basically the beginning of october, or by the second week of october depending on weather in chicago. my white pine, cork bark black pine and alberta spruce will be going in my garage around thanksgiving.

Ok, so I’m on the winter protection bandwagon, here’s my thread about my setup.
I may have made some changes to it since this thread, but it’s basically a heat mat under pots, with infrared heater and fan to blow the air, with a temp controlled vent and fan opposite up high to vent too hot air in sunny days. Also humidifier is essential to keep the air from being too dry when using heat sources. Recently added all LED panels for when they wake before the weather is ready to be outside and a watering system as well, so I’m not chained to them if I want to travel in the winter months. If you have any questions lmk.