It was red last year... It was read in the early spring. Now it all green. Is that normal? Is there something I can do to encourage it to go back to being red?
Completely normal! ;)
Most varieties have distinctly brighter, lighter, or more variegated new/Spring foliage.
There are maples that will stay red during the Summer. Now is a good time to go nursery
browsing for species that you like. I don't advise buying maples in Summer (unless you know
that they've been properly tended). Search now, and then pick up the proper variety in Spring.
Another possibility is reversion (scion dead and rootstock sprouting). It's hard to know for sure without a picture or more info.
Has it been unusually hot? I have a Boskoop Glory jm that turns pretty green during very hot weather.
the simple answer.. in which i specialize.. lol .. is that green tissue is needed for photosynthesis .... and nearly all red trees ... turn green at some time during the year... as a way of producing the food that is needed to survive ... from that point.. it all becomes very complicated.. lol ...
It really depends on the cultivar as was mentioned above...it seems that there are nearly a 1000 japanese red maple cultivars. Is there a database of all the japanese maple cultivars that would be interesting to see.
In the link below is the history of Japanese Red Maples which I think is interesting.
Here is a link that might be useful: Japanese Red Maple History
Here's some more info I dug up on the web:
Japanese red Maple leaves turn from red to green when the intensity of light is decreased.
Most if not all varieties of red leaf plants lose the red color if the leaves are in a shaded area. Our trees are grown close together to conserve water and help keep plants standing.This causes the new upper most leaves to become very red and the leaves that are shaded by other leaves to become green. Once these trees are given more space the red color comes back." (1)
Sorry Ken, but non-green foliage can photosynthesize as well as all-green foliage. The chloroplasts necessary for photosynthesis are still present - it is just that the chlorophyll of the green foliage is outweighed by the anthocyans that produce the red coloring. And there are many red leafed trees that never "green out" in summer. But as others have mentioned, it all depends on the specific cultivar of JM and how it is sited -- some will green up if in too much sun and others will green up if in not enough sun. In either case, it is not particularly unusual and does not indicate any ailment on the part of the tree nor necessarily a reversion in coloring. But as Brandon has pointed out, it also depends on where the foliage is emerging - above or below the graft union. Below the graft union, you may have issues.......
My red maple had been gorgeous for several years - fire red! This year it came out 'green' in is getting more luscious green color the more into fall we go.....why? Nothing has changed, no trees around it. We did however have a cooler and wetter winter in S.C. than years before....would that make a difference?
What kind of maple is it?
Maples are not known for changing colors. Variegated maples often throw solid color reversions and red leaved maples will sometimes "green up" or become more of a bronze color if light conditions are not ideal. But to change completely from red to green is rather unusual, IME.
Weather should not have any bearing other than affecting normal fall leaf color. Is it grafted? Understock can often be quite vigorous and overtake the scion, appearing as though the tree has changed color.......
Japanese maples with red leaves usually turn green in shade. Is this your first year in this house. See if it happens next year.
Sorry, nothing you can do to change that. Except wait until fall when it usually turns a great red.
Japanese maples with red leaves usually turn green in shade
This is not completely accurate :-) It depends on the specific cultivar of red leafed JM. Some lose their red color in full or intense sun, others in excessive shade and some retain their redness regardless of the light conditions. And it's a matter of degree - even in improper light conditions, a red leafed maple will not become completely green. It will usually have a bronze cast, with an underlying red tone.
Watering and soil condition can also have an impact on foliage color, but if the tree has changed completely from red to green, I'd be more inclined to think the rootstock - almost always a green species tree - has overtaken the graft.