Hi Wanda, the problem here is almost the time that you are pruning the trees. Pyrus (Plums) and Prunus (Cherries) should never be pruned in the late autumn or winter. This is because they produce fruit on 'last year's' growth and also because they can easily contract a killer fungus that will enter plants in these genus'sduring the winter through open pruning cuts. Prune the cherries after fruiting and prune the plums in June time- but go lightly a piece every year to reduce the size of the canopy and be sure to open up the centre. Opening the centre will allow air flow and reduce the risk of fungal attack- to which they are VERy succeptible!
Thank you so much Jonathan for your reply and I understand what you are saying. So, now the next question is, do I prune again in June, or leave it until June 2009? Sorry if I sound a bit dim. Apparently this plum tree is the 'off-spring' of a tree that came from France over 60 years ago and was given to my great uncle. He then grew another tree from one of the plum 'stones' and my tree is a cutting of this! What do you think it's chances are?