Green Japanese Maple Tree Leaves Turning Reddish-Orange in Spring

Question: Hello,

Our three year old green Japanese Maple tree leaves suddenly turned reddish-orange in spring.  The leaves were green for a short time.  My husband didn't realize our front yard sprinklers weren't working til after a month or so of warm weather, as we noticed our grass wasn't staying green.  Could the lack of water early in the season be the cause of the leaves turning color, or maybe overwatering?  The leaves are not dried up or dying, just not green.  

I have attached photos of the color the tree should be, and what it is now.

Thank you very much.

Sincerely,
Melissa Reninger

responder: Jennifer  Replied August 26, 2024, 4:45 PM EDT
response: Hello Melissa, Yes, trees' foliage may turn colors early because of environmental stress. From your description, the drought conditions brought on by faulty sprinkling may well have triggered the color change, especially given the very hot weather early in the summer. See the link below. https://www.canr.msu.edu/news/early_fall_color_in_trees_and_shrubs_may_be_a_sign_of_stress You mentioned overwatering. What have you done since the early season lack of water? How much water do you apply to the lawn at a time, and how often? What is the soil like, does it drain well or is it full of clay? Overwatering may be an additional stress. Have you watered in the same pattern in past years, when the tree seemed fine?  How much mulch is around the tree, and is there a bit of space between the mulch and the base of the trunk? Mulch can help insects or disease attack the tree, or maintain too much water if it is excessively deep. It seems that the leaves are not dropping off the branches, but just turned color? Were any other shrubs or trees in the area that did not receive water during that time, and if so, what do they look like? Do you see any signs of other issues, such as insect damage or fungal disease on the leaves? Nutritional stress may also cause trees' leaves to turn color. You might consider getting your soil tested to see if soil characteristics could be making some needed nutrients unavailable to the tree. The soil pH in particular can cause nutrient issues. You can bring in a soil sample to the Extension office to get a pH test done, or send off a sample for more thorough analysis. More information here: https://extension.oregonstate.edu/ask-extension/featured/how-do-i-test-my-soil In sum, you may want to review your watering practices. If they are similar to what you've done in the past (after the sprinklers were fixed), you're putting down an inch a week around the tree, and there is no sign of disease, you might consider getting a soil test done. You also might keep the tree watered for the rest of the season until fall, and see how it does in the spring. This tree should have been well along to becoming established after transplanting, but it will still need regular water.

responder: The Question Asker Replied August 26, 2024, 6:32 PM EDT
response: Hello, Thanks for the reply.  We have not changed our watering pattern.  The tree actually has a new little shoot coming off of it, partially green and partially red.  I think that it probably was the lack of water early in the season that caused the leaves to change color early.  Our plan is to continue watering as normal for the rest of the season, then see how the tree looks next spring.  If it happens again, we'll test the soil.  None of our other plants were affected.Thanks again!Melissa Reninger                    On Mon, Aug 26, 2024 at 1:45 PM Ask Extension <<personal data hidden>> wrote: