Harlequin Maple variegation problem
I have a young Harlequin maple which does not show much variation. I can see, it is still variegated and not reverted to green, but you can barely notice it - from the distance, it looks like plain green maple.
What am I doing wrong? The light is not an issue - the tree gets full sun. What else could trigger the disappearance of variegation?
Here it is:
Some leaves on the top of the branches show a bit more variegation:
And this is what I hoped to get - this picrure is taken from the mature Harlequin maple at the Botanical Garden just a week ago: