Tree mysteries explained OR Question time?

Recently a valued client got in touch with this photograph of a Prunus Amanogawa (Cherry) tree (futher down).

Strangely, shoots had begun to grow out the side of the root stock and he queried what to do.

“I honestly don’t know!” I replied however I contacted my great friend Rachel, Manager of Horticulture at National Trust Cragside.

“It’s the root stock taking over,” Rachel observed. “Just cut the stems back close to the trunk and keep rubbing out new buds.”