A while ago I needed to get my jcb around our field and had to go the route through an area where I had previously planted some quite large holly trees. Our plans changed so they were in the wrong place. I was in a foul mood for some reason and plucked them from the ground with the jcb and carried on working. The holly trees have been left out in the drizzle for a few weeks over Christmas and I have just got around to taking loads of cuttings off them.
I used a little hormone rooting powder, which I have never used before, just to see if they root better. I am wondering if it persists in the ground if you later decide to use that same ground for fruit or veg?
Not an expert here, but from what I have used in the past, all the rooting hormones did persist in the soil. You can however use the new growth of white willow trees, as they contain a similar hormone.