Mikecheck123
Omono
Makes sense, thanks! And fills in part of a mystery from last season.It takes a lot of water to unfurl leaves, and cause leaves to expand. Part of the expansion of leaves is rapid growing of the cells in the leaves, which means stored sugars are needed. If a tree was pulling in through the roots a hypothetical amount of water while dormant, I don't know actual numbers, but say during winter you are watering a tree every 2 or 3 weeks, because that is all the water it was using. Call that amount x then as spring comes, when the leaves start to open you suddenly may have to water the tree daily, water demand has risen to 14 x, or something like that. When you repot you damage the root systems ability to move water. If leaves have already begun unfurling, this can cause them to wilt, or even die back. This means you can even loose branches.
If you repot before the tree begins unfurling leaves, the tree will stall opening buds. It will only open the buds it has sufficient water to open. It is not unusual for trees repotted just before bud break or early in bud break, to not leaf out until a month after its neighbors that were not repotted. The tree will only open what it can support. But by repotting earlier, you don't loose branches
Perfect time to repot is when those brown buds have expanded just enough that you begin to see a green pattern of fine green lines outlining the bud scales. This is when the buds are just expanding but have not opened at all.
Make sense?
Amur maples are rugged trees. It will probably survive, you might not loose much, no matter when you repot. But some of the Japanese maples are really touchy, and repotting late can kill Japanese maples and other tender deciduous trees.
I had a gorgeous little wisteria 4 inches high with a shoot climbing a tiny little pole. I repotted it late (after it had fully leafed out) because it was last on my priority list, but also because, hey, it's a wisteria and they're indestructible!
Not so. It hung on to life for a month or so, but ear wigs finished it off, eating any feeble shoots it could muster.