I often get calls from customers who are really surprised that a tree that was really healthy last summer/fall has started to leaf out, but some of the leaves and twigs then died and shriveled up. Verticillium wilt is a a fungus that lives in the soil, and as tree diseases go, it can really cause a lot of visible die back suddenly.

 In my 30 years of experience diagnosing and treating tree diseases, this is really the only one that regularly shows up early in the growth season. The fungus manages to enter the tree through its root system, then the tree detects it, and tries to counter the movement of the disease by closing off its cells, but unfortunately this results also in blocking movement of water to these which results  in the death of these parts of the tree. Unfortunately, there is not much you can do to stop this tree disease from victimizing your tree, as it lives in the soil. I believe that one thing you can do is to maintain the best possible growing environment for your tree. This includes applying a layer of organic mulch around the base of your trees every 1-2 years to maintain active microbial activity in the root zone. There are microscopic organisms  (fungi) that live in the root zone that a form a mutually beneficial relationship with the fine absorbing roots of a tree; this phenomenon is called mycorrhiza. As the tree disease attacks the tree by entering through the roots, it is believed by many that optimizing healthy microbial activity will help to counter this potential disease from successfully bypassing the trees defenses. Kind of like Probiotics for trees, right? This relationship not only helps the tree protect itself from this tree disease, but it also helps the tree to more efficiently absorb nutrients from the soil that it needs.