Q. What is happening when my red Japanese maple turns green?
There are a number of possible reasons that your red maple is turning green.
- Some varieties retain their red color better than others.
- It is common for red-leafed maple to have red leaves in spring that then tend to turn green in summer.
- Environmental factors are usually the cause. Too strong sun or, conversely, too much shade can cause color change. In sun the leaves may scorch. In shade leaves produce more green chlorophyll to overcome the lack of light.
- Too much nitrogen-rich fertilizer was applied in the spring. Even if you are not fertilizing the tree directly it may be receiving fertilizer applied to nearby lawns or flower beds.
- Growing conditions are too dry. Water the tree well in the summer.
- Very hot summers are also a factor.
- You may be observing a revertant (a shoot reverting to the tree's original characteristics), although in that case you would see one or two green branches or numerous shoots growing up from the base. Many red-leaved maples are grafted onto the green species of Acer palmatum; new green-leaved shoots can grow from this parent.
If the causes are environmental, don't worry. The tree will regain its red color when conditions improve.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service