AusBonsai

Hey guys - I have an advanced Japanese maple.

I’m looking at approach grafting some branches - it’s about the end of spring and going into summer.

When is it okay to put them on?

Hi Daluke , early spring would be better but if its growing it should begin to fuse together , may need to leave the restraints on longer just release and re-wrap /wire in a few months to prevent any long term marks .
Watch the heat of summer if in an open area or use a 30% shade cloth to take the sting out of the sun

Have you considered thread grafting or are you actually approach grafting the ramified branch .

Cheers Ian

I’m approach grafting - I don’t have a good drill bit.

I would approach graft any time of the year. With both parts still on roots there is no imperative to get a quick union. They just keep growing until the 2 parts join up. If it doesn't happen this summer it should happen next spring. Even if it did take that long it would put you ahead of starting next spring.