Toronto part shade/sun 4/5 foot high japanese maple planted 2016 Ugi Gumo
Its problem appears to be WILT. What can be done to save the tree?
Your Acer palmatum ‘Ukigumo’, known as ‘Floating Cloud’ Japanese maple, could very well be a victim of Verticillium wilt, a fungus that attacks the plant’s — either shrub or tree — vascular system. The system is then unable to successfully send nutrient fluids up into its branches, and leaf system. If you had sent a picture, I am guessing we would have not seen cascading, or weeping branches and leaves, but rather limp, underdeveloped leaves.
This fungus is unfortunately soil-borne, and, as you planted your tree just last year, it could have accompanied your tree from the nursery. Since you were able to identify this condition as wilt, is there a chance you maybe had a prior Japanese Maple, planted in the same location, that fell ill with the same fungus. Gardeners do like to plant replacements for their lost treasures, and can easily make this mistake.
Anne Schmidt, volunteer Extension Master Gardener, in an article published April 18, 2016, in The Oregonian, is quoted, “If Verticillium is the problem, the fungus lives in the soil and persists for many years, so you only want to plant a tree that is resistant to the fungus. Resistant trees include birch, dogwood, boxwood, sweetgum and others. Maples and many other plants are very susceptible to this disease. It is very important to pay attention to sanitation so you don’t spread it to other plants. This includes sterilizing any tools used around this tree with alcohol or bleach.” You can read her complete article here.
Also, so you know you are not alone with your ailing Ukigumo maple, with please read this prior post from another gardener with a similar issue, within which you will find a few more helpful links.
Finally for diagnostic and treatment suggestions, consulting an arborist who can make an in-person site visit, is the best best advice. We can suggest you contact Landscape Ontario.