Arne, some varieties show root initials in a couple days. Michael makes a good call using a bubbler. I don't, but I always try to "blast" the water into the rooting jar so there are little bubbles all over the stem. I have to agree also that you can often have better success with green cuttings than dormant cuttings. No need to wait until fall, usually there are little branches on a plant that can be removed during vegetative growth that won't affect the shape of the tree.
Mike in Hanover, VA