After nearly ten years, I'm planting the last wall in the walled garden.

You can see the garden on http://www.go-self-sufficient.com/photowalledg.htm

You can see the north wall at the far right, the inner side has the peaches
apricots, and sweet cherries.

The outer north facing surface has been cleared of vegetation and I have
planted three damsons (that I know do well on a north wall) and I have two
more spaces.

My problem is that makes five different damsons and two pairs Morellos and
Nabelas already.

It there another sharp cherry that would do OK on this wall? Is there any
other fruit that might thrive? I'm stumpted.

Thanks
Pat Gardiner