Freeze protection after repotting?

[C-note]

The generally acceptable practice for repotting includes providing protection from freezes for at least a few weeks after repotting.

Does anyone know why this is? What is different about a newly repotted tree, compared to a tree that has not been repotted?

 

[leatherback]

I do not really protect them for frosts. Had trees freeze solid for a week days after repotting and waking up as if they just took a nap in the spring sun.

The reasons I see are mainly:

- Cutting the roots could trigger a growing response in the roots, which would lower the frost hardiness of them
- Cutting the roots means less uptake of water, resulting in drying out of branches when the tree freezes

 

[Wires_Guy_wires]

Wounds leak fluid, this mixes with water.
When trees are dormant, they make a nice anti freeze mixture in their sap stream. If this leaks out and mixes with water, this sap can freeze more easily.
The water crystals that form can damage the tissue even further. Freezing water expands, and if the root tips are open ended, it'll seep out too.

Combine that with a growth response to injury and lowered water uptake, and it's a recipe for caution.

Some microbes are active way sooner and move way faster than our trees. If they can't repair the damage in time, they'll have exposed entry points for a long time, allowing microbes to enter.

Some plants can handle this with ease. Others have more issues with this.

 

[sorce]

This is easier in summer cause I got too many CornDogs in the freezer!

Welcome to Crazy!

Sorce

 

[Shibui]

This whole idea of protect from frost depends on the 'frost' your trees experience.
Here where nights only get to a few deg below freezing I have never seen any indication of damage after repotting despite all the trees going straight back onto exposed benches.
@leatherback has shown that even frost down to freezing the pots does not hurt hardy species but in some areas 'freezing' is much more serious and may actually do some damage though I have no idea of the mechanism behind it.

 

[C-note]

@leatherback and @Shibui , what you both said matches my experience also. I've had plenty of trees exposed to high-20s temperatures days after repotting with no problems.

I think the idea that bonsai need freeze protection after repotting is another case of us anthropomorphizing our bonsai.