Maple Root Pruning

[JohnFranklin - Zone 7b]

I root pruned my first tree(s) ever, a couple of Amur maples. I realize there is no absolute time but any idea when it will be clear the root pruning is a failure and the tree(s) won't survive? Yes, I am more pessimistic than I probably should be.

 

[Shibui]

Agree you are being overly pessimistic. Amur maple is generally pretty tough so it would be hard to imagine what sort of root pruning would kill them.
Generally root pruning can delay new shoots for a couple of weeks compared to nearby trees.
Occasionally different factors delay budding. Sometimes I've had trees look dead for months but then start growing. It will be clear that the trees won't survive by mid summer but that does not mean that your root pruning was to blame. There are many different reasons for trees to die so don't be tempted to link 2 things together without more proof. I'd expect to see swelling buds way before mid summer.
Just continue care and enjoy the beauty of new shoots emerging.

 

[Leo in N E Illinois]

I have an Amur maple. Nothing will kill it, it is bomb proof. Well, except drought, if you stop watering entirely, usually a week or two of total drought will kill an Amur maple. But cold, hard pruning and most other treatments will not harm an Amur maple.

I have had root pruning delay leafing out as much as a month or two, but usually most trees the delay is only a week or two.