I have a plum tree that is not doing well. It is situated alongside a dirt road which gets regular (but not heavy) traffic. There's not a lot of wind, and the sun shines on it for about half the day.
For the last 4 or 5 years, the branches on my plum tree have been growing in a strange pattern. Every year, there are three zones:
- Bottom zone (red line in the picture above): The lowest thick branches have no twigs or leaves.
- Middle zone (yellow line in the picture above): Branches in the middle (about 6-10 feet above the ground) have sick twigs and few leaves.
- Top zone (green line in the picture above): The top of the tree (about 10-15 feet above the ground) has lots of healthier-looking twigs and leaves.
The sparse nature of the middle zone is hard to see in this picture due to the background trees and the poor camera/photographer (I include a close-up below). In reality the tree looks pretty goofy, because the majority of the leaves are very high off the ground.
Every year it seems the bottom zone gets taller, and the middle and top zones start a little higher off the ground.
Here's a description of the three zones:
The trunk and the thick branches in the bottom zone have lots of lichen. They also have some cracks in the bark which expose orange/yellowish streaks, like this:
In the middle zone, there are a lot of twigs. Some of the twigs have no leaves on them (but did have leaves in previous years). Some twigs have small, dead, shriveled-up leaves. And some twigs have a few, leaves at the ends. Here's a close-up picture of some twigs from the middle zone, where you can see the typical distribution of leaves. There are also some of the dark, shriveled-up leaves in this picture. (In the full-tree picture above, the angle and background trees make it hard to tell the nature of the 'middle zone'.)
This year (and some previous years), the leaves have holes in them, like this:
All the good twigs and leaves are at the top of the tree. They're not great, but they're good and they're the best the tree has. They are packed with flowers every year, and some years I get an occasional small fruit.
They grow tall and there's little or no lichen.
I say they're "good not great" because by this time of year, those top leaves also have lots of holes in them (see leaf close-up above) and the fruit-production is almost non-existent. (I've only got one plum tree, so maybe that's why there's almost no fruit.)
What's causing the slow die-off of this tree from the bottom up, and how do I promote healthy growth on the lower branches?
I have not taken good care of this tree. This means little to no fertilizing and pruning in the last few years. I know I need to feed and prune it, but at this point I'd like to integrate the feeding and pruning with a broader approach to solving the three-zone problem.
I've thought about grafting top branches onto the lower parts of the tree (but I don't have experience grafting), I've thought about severely pruning the top to tree to force growth on the lower branches (feels too risky!), and I've thought about just removing the tree (too passive).
Thanks in advance for your ideas.