Verticillium wilt

So far, I am really pleased with the way my gardening journal is working out these past few years. If you remember, I started taking photographs instead of doing so much narrative in my weekly journal. And the old adage of a picture being worth a thousand words is right. I can compare each section of the garden so much more easily through seeing them in photographs. I never would have believed how much the garden has changed in just a matter of weeks.

I have also documented when and where I move a plant, and it seems I have done quite a bit of moving already this spring. For the most part, things are thriving in their new locations. I did try transplanting a small maple and I’m not sure it is going to survive the trauma. But it wasn’t happy in its old location, either, and wasn’t doing well. I will be patient, though, and give it a few more weeks before I relegate it to the compost pile.

Which brings up another sad matter. Regular readers will remember how much I love Japanese maples. Quite a few years ago, Gary and I bought one to give each other as an anniversary gift. It was called ‘Orido Nishiki’ and its leaves were a variegated light green, light pink and cream. It wasn’t happy in its original location because it was getting too much sun. So I moved it to part shade where I thought it would be happier. Alas, that hasn’t worked either and I can at this point only describe it as a failure to thrive. The interesting point is that it is next to another lovely Japanese maple that is thriving. Perhaps the Orido is intimidated by the beauty of the ‘Ueno Yama?’ (Don’t you just love the sounds of the Japanese maples’ names? My favorite in name and in beauty is ‘Sango Kaku’, better known as a coral bark maple. Her name is just fun to pronounce.)

Back to Orido. I have pruned her back a bit to try to encourage growth but that hasn’t worked well, nor has the increased fertilizer and water. My biggest fear is she has Verticillium wilt. This is a soilborne fungal disease. Once it is established in the soil, it is almost impossible to eradicate. It doesn’t affect all trees, but maples of all kinds are particularly susceptible. The roots of the tree are affected and the fungus spreads through the tree’s vascular system into the trunk and then to the branches.

So now I will need to monitor the leaves for tell-tale symptoms of Verticillium wilt. Some of these symptoms are a dying back of the leaves on one side of the tree, or a branch of the tree will suddenly wilt and die. Leaves are yellowish and smaller than normal or may die and just hang on the dead branches. Eventually, other limbs will wilt and die. The sapwood may show greenish streaks or bands that follow the grain, but this won’t be evident in the earliest stages of the disease.

The worst part is this disease may kill the tree almost immediately or the tree may live for years. If I really suspect this disease, the only way to determine if Verticillium is present in the soil is to do a soil test and send it away for analysis.

Maple leaf showing signs of Verticillium wilt

In the meantime, I will prune away the dead and affected limbs and burn them. If I do this before the leaves fall, they will not further infect the soil below the tree. Disinfecting the pruning and digging tools will be a must before I use them in any other area of the garden. And I won’t over-fertilize with high nitrogen fertilizers so the growth will be normal and not succulent or rapid. I certainly can’t move her to a more congenial spot for fear I would be spreading the fungus to other parts of the garden. Interestingly enough, plants surrounding Orido seem to be thriving happily.

I also won’t be able to plant any of the susceptible plants back in that spot again. Instead, I will move to perennials. There are really no effective chemical controls allowed for homeowners to use.

So I can only hope Orido is just not happy with the site where she lives and is not a victim to this disease. At this stage, I may have to dig her up and inspect her roots to see if they look healthy or are brown and withered. This feels like drastic surgery for the middle of the growing season, so I won’t do that until she goes dormant in the fall. Maybe by then, she will be showing signs of healthy regrowth. Wish me luck as I try to doctor her back to normal.

At least I have my photo journal to document the progress.