I attended a grafting class a few months ago and went home with 5 baby trees I grafted myself and 14 scions of different varieties. When the dandelions were blooming (5/17) I grafted those scions onto some established apple trees (and labeled them). Most have pushed growth (Yippee) and at least two have just flowered. The flowers are a month behind the rest of the tree but they could cross pollinate with each other if the bees look hard.
So, should I leave these flowers on the little grafted twigs or is that too much stress/load for a new graft? If I left them, I'd thin the fruit down to just one apple per scion.
My long term goal with these grafts is to nurture that genetic material so that I can graft them onto new rootstock in the future if I feel like it.
Also, I grafted them with electrical tape. How long should I wait before removing that tape?
I'd say that the usual reason for removing flowers or fruit from new trees is that the tree isn't fully developed enough to support the growth of the tree and the additional requirements of supporting the fruit development. In your case you have a fully developed tree to support the fruit. HOWEVER I wouldn't count on the graft to support the weight of one fruit, let alone multiples.
As far as when to remove the tape I'd say you need to remove it before the tape girdles the grafted branch.
I was glad to see your post as I've been wondering how quickly you can get fruit from a graft on an established tree. My approach was thinking that if I buy a seedling whip, plant it out and later, maybe the same year graft a part of the new tree to an established tree that I could get fruit from my new tree years earlier than if I waited for my new tree do get the job done on its own.
You do not want any fruit weight for the first two years (the graft is the weak link point) so the graft can really get going.
The fact that your graft scion is blooming is a great indicator that the graft took, but it will need to grow at least one new cambium layer to truly seal the graft to the root stock, that means a full year of growth after the grafting year.
The tape should show some signs of swelling of the bark beneath it (new stretching of the tape) or you can do as John mentioned and just watch for girdling effects (bark will swell around the edges of the tape).
Redhawk
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