My 10-year-old plum tree had several limbs that did not leaf out. There was flaking bark at the junction of limbs and trunk, and on larger limbs and branches. There is also oozing sap and cracks on the lower trunk. Branches facing east have produced a good crop of plums. Branches facing west, which include the 'dead' (?) ones have little or no fruit. My apple tree has the same flaking bark symptoms but looks very healthy and has produced a good crop. Any suggestions for treatment?
It might be bacterial wetwood or peach borers or canker, depending on how the sap looks. These articles will describe the nature of the running sap for each problem and will suggest solutions:
https://www.gardeningknowhow.com/ornamental/trees/tgen/wetwood-bleeding-trees.htm
https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm
http://plantclinic.cornell.edu/factsheets/treecankers.pdf
Plum tree did not produce or hold what litte fruit on tree to maturity. Leaves are turning brown with holes and some are skeltonized. I think it was tent worms that engulfed one whole branch and have seen Japanese beetles. There is also an area on a large branch that looks like there is sap coming out of it. I just want to get my tree back to good health, if possible. Thanks for any information you can give me. Judi
Japanese beetles will do the damage you describe. This article will help with getting the Japanese beetles under control:
https://www.gardeningknowhow.com/plant-problems/pests/insects/japanese-beetles.htm
I would also get the tree on a regular spray schedual for pests and fungus. This article will help you with that:
https://www.extension.iastate.edu/Publications/PM1282.pdf
My plum tree has big globs of gum or resin seeping from the bark. What is causing this?
It sounds like you may have peach borers, which also affect plum trees. This article will help you with that: https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm
I have a plum tree in my backyard. It is very old and hardly bears any plums but it gives good cover in the summer. It is covered with a silver hairy disease that is very hard to kill or remove. The birds nest in it and they carry the spores on to my concrete tile roof. The roof is covered in this silver cobweb effect spore and is very hard to remove. I cannot jet spray it off, as it will cause leakage in the tiles. Is there a product that will kill this disease? I have had it sprayed by professional sprayers but it still remains.
It sounds like it may be a form of lichen. Regular applications of fungicide should clear it up. This article may also help:
https://www.gardeningknowhow.com/ornamental/fungus-lichen/treatment-tree-lichen.htm
I have 2 plum trees that I planted last year. I just checked them and they have a split in the branches that I believe to be a canker (fungi). What shold I do? The dormant oil that I use on my apple trees does not list plums on the lable.
The dormant oil you have should be fine for the plum tree. I can't say 100 percent for sure, because I don't know exactly the brand you are using, so you may want to call where you bought it at and ask a nursery worker to confirm that it is safe for plums.
I was away last summer. Upon returning, I found tree was almost totally dead. Sap was oozing on branches. Leaves died but did not fall. New growth this year from top of trunk and a few branches. I now see some of the new growth is dying. I just cut back some of the dead branches. Tree is about 25' high and 30 wide. Should I continue to cut back and what can I put on it?
This is either caused by borers or by a canker. In both cases, if the tree is badly far gone, then it would be more beneficial to you to replace the tree rather than trying to save it. If you can get the tree to recover, it will take years to recover its former state. Better to start clean and get there with a fully healthy tree.
Its leaves are turning red to yellow and falling off. It is a Santa Rosa plum tree.
It may be a nitrogen deficiency. A severe nitrogen deficiency can make the leaves red and yellow and prone to fall off. If you are also seeing spots, it may have bacterial spot.
Try giving the tree some fertilizer and if you suspect bacterial spot, this article will be helpful:
https://www.gardeningknowhow.com/edible/fruits/plum/plum-tree-diseases.htm