Why is my red Japanese maple turning green?

You can expect the leaves to green up if the tree is in less than full sun or where light levels are not ideal. Summer heat, chemical fertilizer, and immaturity all can cause greening of the foliage. Some Japanese selections green up more than others. If you desire a purple Japanese maple shop for it in the mid-summer. This is the time when Japanese maples will green up if they are going to green up.  A morning sun location is best. Some red-foliaged Japanese Maples will turn green in intense sun and others will do the same in too much shade. It depends on the tree. Many "red" Japanese maples are known to green up a little in the summer. The leaves should be red in the spring and fall. Also, in the heat of the summer, the plant burns carbohydrates faster when the nights are warmer, which can result in loss of colors other than green. This is normal. Don’t worry, it will be brilliant in the fall, and next spring too, when it leafs out again. Make sure you are keeping the roots evenly moist and that the soil drains well.