Do we really know the differences between watersprouts and suckers? It seems simple enough. The definitions of each should be rather distinct.

When I grew citrus, I knew what sort of sucker that I had to contend with. Suckers were any unwanted stem and foliar growth from the understock below the graft union. In the picture of the trunk of the young plum tree above, the graft union is clearly visible between the scion to the upper left and the understock to the lower right. Suckers would be below such a graft union.

This sort of sucker is known as such because it sucks resources that should be directed to the more desirable but often weaker scion. A sucker that is more vigorous than its associated scion is likely to overwhelm and replace it if not removed. Scions are expected on freshly grafted plants, but should become less prevalent as…