Are there any current recommendations for a "self-fertile" plum tree in the lower mainland? So many varieties seem to be prone to black knot and other diseases. Thank you.
I have 5 varieties of plums grafted on one tree, and the one that is most useful is an Italian prune plum. This variety is productive and self-fertile; and the fruit is tasty, freezes well, and can be dried. All of the others are Japanese plums, and I can't recommend any of them. Santa Rosa is the tastiest plum that I've tried but is not very productive. Occasionaly there is a good crop, but usually only a few fruits ripen. The most productive Japanese plum is the yellow Shiro plum, but it is very watery and nearly tasteless. I think that most, if not all, plum varieties are susceptible to Black Knot, but I have not found it to be a problem with my tree. I see small infections occasionally, but they are easily removed. I even cut out a fairly large infected area on the main trunk years ago, and the area quickly healed over completely. The only other disease that has bothered my plums is Coryneum Blight, but that is the result of having a very susceptible peach tree nearby. The Italian prune is less susceptible to Coryneum Blight, but it does get aphids, which are much easier to control.
A friend has an old damson plum in her yard that produces a lot of plums - enough for jam and to put away for pies for her communal house and occasionally for her band get-togethers long into the winter. But she says it does have a bad case of Black Knot.
Stone fruit are very susceptible to damage from the fungus and bacterial diseases that are prevalent in the cool humid climate conditions of the Puget Sound region. Also the lower seasonal heat levels, compared with regions such as eastern Washington or California, may not produce the high quality and flavor of the common commercial varieties. Some pollination problems occur when bad weather at bloom time limits bee activity, especially for early bloomers like apricots and early plums. Stone Fruit | Western Washington Tree Fruit & Alternative Fruits | Washington State University
we just cut down a 3 year old peach tree because of oozing bark and leaf/branches dying: ( no diagnosis) now I suspect the the 4 year old plum has picked up something: it looks like peach curl on the leaves and lots of small twig death: Is this the Coryneum Blight you speak of? txs.
What variety is the plum tree? If it is an oriental variety, it might be susceptible to Coryneum Blight (AKA shothole disease), which usually appears as spots that turn into small holes in the leaves. There can be some leaf curling and yellowing, followed by loss of leaves; but it doesn't show the leaf thickening that is typical of Peach Leaf Curl, which I have never seen on a plum tree. Peach trees are also susceptible to borers, which are likely to have caused the oozing that you mentioned and could have killed the tree. I think that plum trees are less susceptible but not immune to borers; I have not had problems with them on my plum tree.
Thank you for the feedback: do not know the name as my hubby bought a 'fruit salad' tree; I had advised against it as most of the time only the dominant branch will thrive. Will research Coryneum Blight further. Yes, the peach curl type of leaf threw me. Cheers