“I recommend using a slow or controlled release type fertiliser. Commercially known as Polyon or Osmocote, these are the most common and both work very well on Japanese maples. We use both successfully in our Japanese maple production.”
For newly grown or transplanted Japanese maples, it is important not to fertilise right away, according to gardening pros at Gardening Know How.
They said: “It’s important to apply fertiliser to plants at the appropriate time. The first rule to keep in mind is not to start fertilising Japanese maples too early. Don’t think that a newly transplanted tree needs feeding immediately.
“Once you plant the trees, wait at least until their second growing season before fertilising Japanese maples. You’ll want to give the plants ample time to adapt to their new conditions. When you do start feeding Japanese maples, do so in late winter while the ground is still frozen. Alternatively, start Japanese maple feeding after the last freeze in spring.”