Most species of Loropetalum bear maroon, purple, burgundy, or even nearly black leaves presenting a unique foliar aspect for the garden. Occasionally your Loropetalum is green, not purple or the other hues in which it comes. There is a very simple reason for Loropetalum leaves turning green but first we need a little science lesson.
Reasons a Purple Loropetalum Turns Green
Plant leaves gather solar energy through their leaves and respirate from the foliage as well. Leaves are very sensitive to light levels and heat or cold. Often the new leaves of a plant come out green and change to a darker color as they mature. The green foliage on purple leafed Loropetalum is often just baby foliage. The new growth can cover the older leaves, preventing sun from reaching them, so purple Loropetalum turns green under the new growth.
Other Causes of Green Foliage on a Purple Leafed Loropetalum
Loropetalum is native to China, Japan, and the Himalayas. They prefer temperate to mildly warm climates and are hardy in USDA zones 7 to 10. When Loropetalum is green and not purple or its proper color, it may be an effect of excess water, dry conditions, too much fertilizer, or even the result of a rootstock reverting. Lighting levels seem to have a large hand in leaf color as well. The deep coloring is caused by a pigment which is influenced by UV rays. In higher solar doses, the excess light can promote green leaves instead of the deep purple. When UV levels are promotional and plenty of the pigment is produced, the plant keeps its purple hue.