If there is no chance of freezing, is it ok to repot in the winter? I have an Australian Tea tree that is in dire need of repotting and is starting to lose branches. I wanted to repot ASAP but also wanted to make sure doing it now wouldn’t make things worse
I saw this post on the reddit forums and wanted to reply to it here instead. What a surprise!
I’m curious on this too. Where I am it drops to maybe 30’s and gets up to 65 roughly in the daytime. I figured it would be better to repot early to give the roots time to develop and grow. Maybe they don’t grow if I take away too many of the resources it gathered.
Thoughts?
When we repot there is always damage to the roots. Even if you are careful, the root hairs will break which mean they will struggle to maintain the balance of what’re and oxygen. Concquentialy, they need a period of recovery. If these damaged roots are then frozen, it makes that recovery harder for the tree.
If you need to repot in the winter, then repot in the winter, but it is important to understand why it is not the best time, and to provide solutions to the problems that repotting at this time of year may throw up.
Good luck, and try to keep them from freezing.
I would think that if you can put it on a heat mat then it might be ok to take the risk.
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So is the only problem with Winter repotting the freezing temperatures and not timing before buds break, anything with the tree tissue or anything like that? If so I’m fine to repot without any issues basically after leaf drop. After repot I can leave it in the East facing window inside my unheated garage during recovery.
Is my logic wrong? I feel like I’m skipping some important thing.
It all depends on the severity of the root work. If it is major it is a problem as all the energy stored to produce the first flush will have been lost on the cut roots. If it is minimal and you can keep the tree above freezing and the roots active with a heat mat, that will maintain metabolic activity and allow the roots to regenerate.
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Yeah I think it all depends on a lot of factors.
If it’s deciduous, I wouldn’t do it if it’s going to be a severe root prune. But if you have a mature rootball and it’s going to be a minor trim of the roots then maybe it’ll be okay if you have winter protection (or mild winters). But YMMV
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Hedging plants are often planted in late autumn. Root activity will often continue through the winter, when not freezing. The more damage we do, the harder it is for a tree to recover. If the tree is already weak- emergency repot, the odds go down. That is one reason a spring repot gives the best chance of success- tree is moving energy and can repair.
I think it’s iffy for all the reasons above. Repotting always damages the tree’s roots, which has two consequences:
- Reduced capacity to intake water and oxygen;
- Loss of whatever resources are currently stored in damaged roots.
Regardless of why you’re repotting, you have to make sure the tree survives.
If you repot when the tree is inactive or barely active, it’ll need to survive until its next period of root growth AND you’ll have lost a bunch of resources for the spring bud push.
Even in a non-freezing climate (that’s my situation too – it’s currently 60F outside), I’d wait until buds start to swell. At that point, the tree’s moving resources and you have a much wider margin of error for root damage (because the tree’s already pushing leaves, which in time will create resources for root creation).
Especially for an established tree, especially for an evergreen, and especially if you’re only doing very light root work, you’ll probably get away with it. But why risk it unless you absolutely have to? If it’s just bonsai fever, wait a couple months; trees take patience. 
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