I have 3 small Carmine Jewel cherries in a large pot (each only about 8 inches tall at this point; this is my 2nd summer with them -- they are still so small due to deer pruning last year). Potted in sandy compost. They have leafed out well but today I noticed that the leaves are starting to yellow while maintaining dark green veins.

I assume this is a nutrient deficiency, perhaps because of our recent heavy rains? I have kept them in the pot waiting for this time of year to pass just because it is so wet, and I haven't been able to prepare a raised, well drained area for them yet.

Any suggestions? I will appreciate your advice!