Vine maple turning red in summer
Some leaves on our vine maple are turning red in late June/July, while other leaves are still green. I have seen conflicting information online as to whether this is natural for the species or if it indicates that the tree is stressed. If it's an indicator of stress, what should we do?
Multnomah County Oregon
Thank you for your question. I believe that I am seeing, but want to confirm, that the red leaves are appearing on only one or two branches. When this phenomenon happens, it is often the result of a soil fungus (untreatable). But, before we go down that path, please let me know how many branches are showing this. Thanks!
It's definitely worse in one area (maybe 3 branches?), but also occurring at the top and sprinkled throughout the other side. I circled the spots in one of the photos. It is concentrated where the tree is getting the most afternoon sun and also in the path of our sprinkler.
Thank you for further information. Let me comment on a few issues of this species. They do not do well in full sun. They are relatively shallow rooted plants. They need more water than some other maples. So, your plant may be struggling with issues related to its location. Too hot, too dry, too much sun. The red leaves may also be a symptom of a nutrient deficiency. How often do you fertilize? I suggest you read the following Extension article to see if it provides guidance: https://ask.extension.org/questions/358786 Good luck!
Thank you for your response. It was very unhappy when we arrived, but since adding a rain garden nearby it started growing a lot. However, we have not been fertilizing. Should we use a fertilizer with phosphorus or nitrogen?
Your plant needs a balanced fertilizer (nitrogen, phosphorus and potassium) with 10-10-10. These are the macronutrients. Our clay soil typically contains adequate amounts of the 13 micronutrients. Get an organic or time release fertilizer. water soluble ones just quickly find their way into the aquifer, rather than providing 'food' for your tree.