I have a healthy 30+ year old orange tree, taken over by the rootstock so that it produces sour oranges. I've been wanting to graft it over to other varieties and collected some scionwood, but I've been checking the bark since spring and it still isn't slipping. I can make a cut and try to force open the bark on either side of the cut...but most of the time when I do this, I damage it because it's sticking and doesn't really want to slip open.

Are some trees like this all the time? Could I have missed a narrow window of time when it did slip? Any information would be helpful.

John

In general bark will slip when the tree is flushing. I don't know where on your tree you have tried, but it is more difficult to graft on old wood--the best sites for grafting are on wood that is still very green with only a few streaks that the wood develops as it gets older. If you are trying to graft at the base of an old shoot, you would probably do best with bark grafting. Then if the bark graft fails and you get a vigorous new shoot develop, that will be very good stock for T-budding.

You can use chip budding and cleft grafting when the wood does not slip.