I have had this tree for 12 years,and now some growth is changing from red to green.Is this a genetic problem?
Dis-colored Crimson Queen Mine turned green also, but all the new growth is red. Does anyone have a suggestion on what might be the problem?
I believe that the red color in Japanese Maples is a result of sugar produced by the leaves. Most of the red forms will bronze late in the season as the days get shorter and there fewer hours of daylight for food/sugar production. Some cultivars will stay red longer than others. The same cultivar will appear to bronze (turn green) sooner if it gets less daylight. Your tree may be getting less light and more shade due to trees planted near by growing and casting more shade on your tree than it did a few years ago. Also as the tree grows, the leaves that get the most light and retain the red color the longest are higher from the ground and not in view. The leaves on the lower branches are shaded by the upper branches and my never be very red. An interesting note is that Japanese Maple cultivars that are red usually will remain red longer in the summer if they are planted in more northern latitudes. An example would be that an A. p. 'Bloodgood' might turn green by August 15th in Atlanta, GA, but remain red until September 1st in New York, NY. Both may be planted in zone 7, but the hours of sunlight are greater during the summer in more northern latitudes.
I think that, along with shortening daylight hours, temperature variance and exposure, night time temperature plays a large part in the coloration .
Yes, higher night temperatures cause higher respiration during the night which consumes the sugar/food that was produced during the daylight hours which may result in a net reduction in the surplus sugar that keeps the color red. Longer daylight increases food production and cooler nights result in less food consumption.
I recently planted two Japanese Maples. One gets 3 hours of direct sun a day. The other is in shade almost all day. They have both lost the red color that they had when first planted. These trees were grown in this area so I'm not sure that either the temperature or amount of sun can explain their loss of red color. Would fertilizer make a difference?
Hi, the question is at what time of day does your maple get its 3 hours sun, if it is early in the morning, it is probably that there is insufficient heat, as mention before in this thread, to produce the sugars that enhance the red hues in the leaves. Some cultivars revert to green quite quickly if put in the shade, or receive in sufficient sun. It can take up to 2 years before your trees settle in to their new environment, or even put on new growth,maples in general terms do not like deep shade. If you feed them to much with a nitrogen rich fertilizer, in red cultivars, sometimes this will induce a greening of the foliage, you should not feed them at this time of year in any case, as they need to harden up for the approaching Autumn. Which variety do you have, as this also will have a bearing on the performance of your trees.
Is this the first year that they have lost their red color? I noticed yesterday on my walk that nearly all the Japanese maples on my route (all but one, actually) have turned green and they never have before (in previous years). They are all different sizes/ages. Some are so green they look like green JMs. You're close to my location so I'm wondering if maybe weather conditions this year could be causing this effect and you may have a different result in years to come.
