Pruning Weeping Cherry Trees and Other Grafted and Budded Ornamentals - Page 4
Once again since the graft union is at 5', any growth coming from the stem (rootstock) must be removed. In this case the growth coming from the rootstock will be Hawthorn and will look completely different from the Cotoneaster which is what the plant is supposed to be. The easiest way to keep up with this type of pruning is to keep an eye on your grafted plants when you're in the yard. As soon as you see new growth coming from below the graft union, just pick it off with your fingernail.
If you catch these new buds when they first emerge, pruning them off is as easy as that. Walk around your yard and look for grafted or budded plants, and see if you can find any that have growth that doesn't seem to match the rest of the plant. Look closely and you may find that the growth is coming from below a graft or bud union.
