Two Questions: One, rose leaf drop and, Two, plum fruit shriveling

Asked June 30, 2015, 5:14 PM EDT

If I can get a twofer..... One, a rambling rose, mature, good blooming this year, then right after blooming the leaves started yellowing, small black spots, and dropping off until it is now nearly bare.Seems to be dying from the bottom. Sited where it gets full afternoon sun. Good drainage. Gave it a little milorganite twice this spring. Two, a four or five year old damson plum tree quite healthy looking. Last year was first bloom year. Last year and this year the fruit all shriveled shortly after appearing. I do not see one living piece of fruit on the whole tree. It is next to an italian plum tree which nearly died from, I think, Spike put down by the railroad when it ran through here, but that tree has sent out some healthy sprouts but no fruit. My hunch is to cut it down and replant with another plum which will pollinate with the damson. But why such shriveling? Thanks,

Anne Arundel County Maryland

2 Responses

1. Rose: These are the classic symptoms of black spot, a common fungal disease that roses get. First they get black spots and then the leaves yellow and fall. You will need to spray with a fungicide with black spot on the label. The fact that you have not have problems with black spot before is a good sign.
Try to pick up the infected leaves that fell off, in order to get infected material out of the area. Next spring, you may want to spray with a fungicide as soon as you find the first black spot on the leaves.

You may find that black spot is a problem in years with long periods of rain (June set a record here), but in dryer years you won't have much of a problem. Also, your rose may have become denser with age and the air circulation may not be as good to dry off leaves (so some pruning is in order.)

If the problem becomes chronic and debilitating, you may have to replace your rose with one that is more disease resistant. Here is our website info:


2. Plum:

Your plum with the shriveled fruit could have many possible causes for the fruit loss: lack of pollination, over-fertilizing, insects such as plum curculio or a disease such as brown rot. You may want to cut them open and look for worms or insects. Brown rot would cause fuzzy mold. If you send us a photo, that may be helpful for a better diagnosis. (Incidentally, Damson's are self-fertile, so they do not need a pollinator tree.)