If the tree in your photos is a Prunus mume, you can prune it significantly without harming the tree.
Do that either right after the flowering period in the late winter or in the late Fall after the leaves drop and when the tree is dormant if you don't care about seeing the flowers.
These are often grown for the flowers rather than the fruit, so most people prune after the flowering period but these people aren't usually trying to collection scion wood so I'm not sure of the proper time if you want to graft what you cut.
Some cultivars are popular for bonsai.
Prunus mume grows quite fast and some cultivars will put on as much as 5-7 feet per year for the first few years. Prune back 2/3 of the new growth (after it flowers if you are into seeing those) and it should be fully leafed out again by mid-summer.
I just lost a 3 year old tree that had been growing nicely. I think it was a soil / root problem combined with August heat last year and probably lack of watering. It died very quickly.
I now have 5 different cultivars that I grew in pots for the past couple of years and they are still small. I just planted them in the yard last fall so I have not seen them bloom yet in their new locations, but they are full of buds. I believe that all of them were grafts. None have fruited yet. I think I remember that they take about 4 years to start producing fruit.
I have not met anyone who says the fruit from Prunus mume tastes good.
We'll see.
Bill Blevins
PlantsMap.com--