QuestionI live in northeast Ohio. I rescued a very small Crimson King maple sapling that was growing next to a greenhouse that was going to be torn down. The sapling was only about 4 inches tall. For 3 years I had it planted in a shady place next to a deck where it could get stronger and more developed before moving it to a more suitable location. For the first 2 years it was fine and was crimson, as it should be, from the onset of its leaves in spring until fall. Well, by the third year, my husband accidently weed-whipped a portion of the sapling. It grew back, however, the leaves were not very crimson except at the very top and it was not growing very well. We moved it to a fertile full-sun location this year (year #4) and although it is now a good 3 feet tall and it loves the new location, it is still more green than crimson. What happened? What can we do to correct this? Or, is this not the Crimson King I thought it was? Please help!
AnswerIf it was a crimson when you first moved it it still is. I think the tree is reacting to the many moves and stress that has been put on it the last couple of years. The leaves are young from the new growth. Over time if not moved again it will return to the "normal" leaf color. Let it alone and wait until next spring. It should be ok.
Anthocyanin pigments are responsible for the pink, red, and purple leaves of sugar and red maple, sassafras, sumac, white and scarlet oak, winged euonymus, and many other woody plants. They are formed in the cell sap inside the vacuole when sugars combine with complex compounds called anthocyanidins. The variety of pink to purple colors is due to many, slightly different compounds that can be formed. Their color is influenced by cell pH. These pigments usually are red in acid solution and may become purplish to blue if the pH of the cell sap is increased.
Anthocyanins are usually not present in leaves until they are produced during autumn coloration. A few trees, however, such as 'Crimson King' Norway maple and purple European beech have reddish leaves throughout the growing season due to anthocyanins in them. Not all trees have the genes required for production of anthocyanin pigments, and hence those trees only develop yellow and brown shades of autumn color.
Formation of Abscission Layer
Shorter days and cooler temperatures in fall initiate leaf senescence involving complex biochemical processes, which increase the enzymes in leaves that promote the breakdown of cells. One of the results is the collapse of cells in the living phloem to form an abscission layer at the base of leaf petioles where they attach to twigs. This is the point at which a leaf is eventually shed. The nonliving xylem tissues remain intact for awhile and still carry water to the leaves, but the phloem pathway for conduction of sugars out of leaves is severed. Sugars, derived from continued photosynthesis as well as from the conversion of stored starch to soluble sugars in the leaves, are trapped and are available for anthocyanin production. Trees of the same species growing together often differ in color. The colors vary because of differences in amounts of soluble sugars in the leaves for anthocyanin production. Trees exposed to the sun may continue photosynthesis and turn red while others in the shade may be yellow. A single tree may even have branches with different colored leaves due to one leaf shading another.
It could be the combination of the weather, sunlight and the age of the tree. As the tree gets older it will show the color better. I would fertilize the tree next spring to encourage foliage growth. Use 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered under the tree and water in good.
