Can anyone lend insight into why a couple of my 4year old fruit trees keep splitting their cambium/bark layer? One is an Red Ace plum. It has not grown more than 5-6 inches since planting. Last year it put out 3 small but healthy fruits but none this year. The other is a pear (don't have type with me). It HAS grown probably 2 feet in same amount of time but never put out fruit. Both are fenced against deer and fertilized with stakes each spring.
Some splits are a couple inches long, some 8-10 inches. The bark and camb layer are sort of pulled or shrunk back gradually and expose the heartwood very obviously. It is all healed looking and not raw. These can be found from ground level to top in various places on both. I see no signs of insects or animal damage. I did have one of those white plastic anti-girdling tubes on them the first couple years since this is in northern Michigan. The plum even has the heart wood protruding above the top branch - looks like a dowel sticking up beyond the tree an inch. At the same time and in the same yard I planted an apple which is doing very well and a cherry which has grown to 15 feet tall and is a great producer! It is such a head scratcher to me and I sure would like to do whatever I must to save them. I know these are grafts, bought from a nursery but do grafts have this problem? Thanks.