Hello everyone, I'm Lynn, the new girl on the site, and live in Devon, UK. My passion is tropical trees, favourite Flamboyance.  I have 4 just now, sown 27 April 18 and going like the clappers, sturdy and full of new growth.  Was wondering when is the best time to repot?  Anyone know?  They have been outside all summer when it's been hot (20-27C) now brought into airy glassed-in porch at night, +/- 10C.  When they sleep, I'll keep them pretty dry and cool until spring. I can post pics when I find out how!

I have never found it necessary.  I have had to simply concentrate on keeping the growth toward the center of the tree making grafting unnecessary.  In all honesty I am not very good at grafting and I avoid it at all costs.

When the temperature of the greenhouse is lower than 6?, no cold injury occurred in one week, and the effect of grafting seedlings to Cucumber Fusarium wilt was generally above 90%, and the total yield is more than 20% compared with the root seedling.

Very cool, beautiful. Do you know how about its planting environment?

I want to plant in my garden.

Quick update:

It was successfully repotted that September. This wasn't a "slip-pot", but rather a thorough removal of dead roots and replacing garden center soil with an inorganic bonsai mix. I responded with healthy new growth the following spring but sadly died later that year due to my untimely wiring in late August - the loose cambium separated from the heartwood.

I now, however, have 2 JWP in the ground at my parents' upstate NY home and two recently purchased seedlings in plastic pots with me in MD - all are base species on their own roots, not cultivars.

The 2 growing in the ground were also previously in plastic pots. I found they did better in regular plastic pots than those that were growing in colanders, which I suspect had to do with the colanders being less stable on windy days than the flatter, broader bottomed pots. Also, the JWP in the colanders all died when being transplanted into the ground, this was done in autumn, so I cannot make a general recommendation for repotting JWPs then. The main cause of their demise is still unclear. The 2 JWP that were in plastic pots and were successfully transplanted (in early spring) in the ground are root pruned every 3-4 years. 

 recently relearned from Julian Adams (owner of Adams' Bonsai) the utmost importance of keeping JWP very stable in their pots. "Keep them thinking their in the ground," he said. JWP will grow poorly when their roots are disturbed by even the slightest rattle of the pot caused by wind, over-handling, and/or loosely anchored roots.