Popular because of both their breathtaking beauty and general hardiness (two qualities that make them excellent choices for adding to virtually any garden or landscape), Japanese maple trees are known primarily for their bright crimson foliage.
Even with their widespread popularity, however, many people don’t understand when Japanese maple trees turn red or even why they exhibit these dramatic color changes. The simple explanation for why Japanese maple trees change between red and green relates to the various pigments in the leaves and how certain weather and temperature conditions affect those pigments.
In order to help you better understand this fascinating phenomenon, we’re going to discuss the matter in greater detail. We’ll go over not only the science behind these color changes but also share with you some information about what might trigger the switch from red to green (and vice versa). We hope you find this information interesting!
Japanese Maples Begin Spring New Growth With Red Foliage
While it’s easy to say that, in general, Japanese maple trees start with red leaves in springtime, the reality is slightly more complex and depends on a few different factors.
Some of the factors that can affect leaf pigmentation include (but are not limited to) the weather and temperature conditions where you live as well as what type of Japanese maple you are growing.
Additionally, as we will discuss momentarily, not all maple trees are created equal when it comes to when they develop red leaves (or if they ever display red leaves at all) so it’s important to understand these details when learning about these marvelous trees.
Only Specially Selected Japanese Maples Begin With Red Leaves
As mentioned above, not all Japanese maple trees begin with red leaves; rather, there are certain cultivars that possess this quality. Two of the most well-known of these varieties include Bloodgood and Suminagashi, both of which are known for their brilliant red and deep crimson foliage, but there are quite a few others as well.
Naturally, the reverse of this is also true: some Japanese maples begin with green leaves and don’t turn red until a change of the seasons occurs. And there are other cultivars that never turn entirely red, instead displaying gold or orange leaves.
The red color itself is the result of anthocyanins and carotenoids; these botanical pigments are responsible for the colors such as red, orange, purple, and blue when seen in plants, and it is the presence of these pigments that results in the distinctive shades of crimson seen in Japanese red maples.
Though, as we mentioned before, not all varieties of maples possess anthocyanins and carotenoids in such high quantities as to outshine the chlorophyll in the leaves (which is responsible for green coloring).
As such, if your goal is to grow a Japanese maple with either red leaves or leaves that will eventually turn red, it’s important that you have at least a general understanding of these different cultivars. Understanding the type of maple tree you’re dealing with can help you better understand why and when its leaves may change color.
Some Trees Develop Red Leaves As The Weather Changes
While there are some varieties of Japanese maples that remain red all throughout the year, other cultivars begin with green foliage before changing color to red. This, of course, leads many people to ask: why do these trees change color? What triggers it? The answer in most cases is: because of the weather. Specifically, the weather and lighting changes that come with the changing of the seasons are often what cause trees to turn red.
As mentioned earlier, the color of maple tree foliage in general relates to the various pigments found in the leaves; green comes from chlorophyll while the more vivid colors such as red and orange come from anthocyanins and carotenoids (which we discussed briefly earlier).
While these pigments are usually always physically present within the leaves during all seasons of the year, the brilliant red colors they create sometimes only become visible when the weather changes in the autumn and causes the green chlorophyll to break down. The longer nights that come during the fall and winter months can also be a contributing factor to this color change.
Japanese Maples Begin To Turn Red And Orange During Fall
There are certain things that can trigger a color change in Japanese maples, but in many cases, it is safe to say that most maples turn red in the fall.
On that note, let’s dive into this phenomenon. We’ll also go over a few exceptions to it. It is our hope that this information will help you to gain a greater understanding of these seasonal color changes. It can get confusing, but that’s why we are here!
Most Maples Turn Orange Or Red In The Fall Months
As we discussed earlier on in this article, the two most common triggers for a color change in Japanese maple foliage are temperature and light. (There are also certain types of damage that can cause color changes, but we will go over those types of situations a little later on.)
Since autumn is often the time of year when you have colder temperatures and short days with less light, it should come as no surprise that fall is the time of year when most maple trees begin to change color from green to red (as the chlorophyll begins to break down from reduced sunlight and warmth).
Exceptions to this include varieties of Japanese maple that don’t usually turn red in any circumstances. Some cultivars, for example, typically exhibit green foliage that will change color to yellow or gold once autumn hits but never darken to orange or red. Any Japanese maple trees that are experiencing certain types of nutrient deficiency might also see an impact on their coloring.
Why Is Your Red Japanese Maple Turning Green?
To have your Japanese maple tree suddenly begin to turn from red to green can be not only confusing but also alarming, leaving you to wonder if this change in coloring is normal or a sign of some problem with your tree.
Generally speaking, Japanese maple trees are fairly hardy once they are well-established in their environment. That being said, when it comes to these marvelous trees, there are certain conditions or types of damage that can affect not only their health but also their coloring.
In order to help you better understand these color changes, we will now discuss reasons why a red Japanese maple tree might turn red. It is our hope that this information can help you to better understand not only the color change process itself but also when to be concerned about it.
Red Maples Will Turn Green If There Isn’t Enough Sun
Japanese red maple trees are known for not only their vibrant foliage but also their love of sunlight. These trees prefer growing in full sun, although some varieties can grow alright in partial shade. In fact, these trees love sunlight so much that if they do not receive sufficient sunlight to remain healthy, they may begin to fade from red to green (or even pale yellow).
As such, when first planting a maple tree in your yard or garden, it’s important to place it somewhere where it will get plenty of sunlight not only as a sapling but also once it grows larger and reaches maturity.
Generally speaking, it’s best to avoid planting a Japanese maple tree too close to your home, outbuildings, or any other large trees that might block sunlight from reaching it.
Check out our article on How To Get A Japanese Maple To Thrive In Full Sun.
Damage To Red Maples Can Cause Them To Turn Green
While the specific symptoms can vary depending on the actual underlying issue, certain types of damage and botanical diseases can sometimes cause leaf discoloration in Japanese maples, including a shift from vibrant red to green or even yellow.
According to the Iowa State University Extension, one of the most common causes of this sort of color change is Verticillium wilt. This fungus can cause a variety of different problems depending on the severity of the situation, but one of the most obvious symptoms is the leaves wilting and turning yellow or pale green at a time of year when they should not.
Overwatering can also cause discoloration in Japanese maple tree foliage, although in most cases this will present as brown or black splotches at the tips of the leaves rather than green. Additionally, if a Japanese maple tree is still young and has not yet reached full maturity, new branches may produce green leaf growth rather than red.
If you need help identifying concerning symptoms in your maple tree, check out our guide including the 9 reasons your maple’s leaves are brown.
Improper Fertilization Can Cause Red Maples To Turn Green
It might come as a surprise to the average at-home gardener, but fertilizer can impact more than your tree’s overall rate of growth. Specifically, the chemicals and minerals contained within certain fertilizers can impact not only your tree’s health but also its color.
One of the most common causes of red maple leaves turning green is a nutrient deficiency caused by inadequate fertilizer use; if you do not use enough fertilizer (or don’t fertilize frequently enough) your tree will not be receiving enough key nutrients, which in turn can impact the tree’s health and also cause the leaves to change color from red to green.
Manganese in particular is an important nutrient for Japanese maple trees (manganese in general is a very important micronutrient for plants, and is critical for chloroplast development as well as photosynthesis), and not getting enough of it can cause leaves to turn green or sometimes even yellow.
As such, it’s important to use fertilizers that are both appropriate for Japanese maples and that have all the necessary nutrients. We will provide you with some fertilizer recommendations a little later on in the article; we hope you find them helpful.
Read about our picks for the 5 Best Maple Tree Fertilizers (And How To Use Them.)
Too Much Heat Can Cause Red Maples To Turn Green
While Japanese maples are trees that typically thrive in conditions of full sun, environmental conditions involving too much heat can often have a detrimental effect.
Generally speaking, most Japanese maple trees do best in USDA Hardiness zones 5 through 8 (although there are some more delicate cultivars that prefer the more moderate temperature ranges of Zones 6 or 7 specifically).
If you see the leaves of your Japanese maple tree begin to turn pale green or curl in at the edges, it could be a sign that it is enduring too much heat or experiencing too much intense sun exposure.
For more help handling hot weather, take a look at our watering guidelines for your maple tree.
How Do You Get Japanese Maple Trees To Turn Red?
If you have a Japanese red maple tree that isn’t currently red for whatever reason, you’re probably asking yourself not only ‘why isn’t my maple tree red?’ but also ‘how can I get my maple tree to turn red?’.
Since we’ve already gone over some potential causes for why your Japanese maple tree might turn green instead of red, we will now discuss some tips for encouraging red coloration in your tree’s foliage.
Mild Days And Cold Nights Can Cause Japanese Maples To Turn Red
Generally speaking, Japanese maple trees do best when grown in conditions ideal for their health and development. In most cases, this means that they will display their signature red foliage when there are mild days with plenty of sunlight (but not too much heat) and when there are slightly longer nights with cooler temperatures.
Since there is little you can do to actually control the weather, all you can really do is be patient and operate with the understanding that even if your Japanese maple tree has not turned red yet, it will most likely do so once the weather changes to the appropriate conditions; as discussed earlier, these weather changes normally occur in the autumn and winter months, so that is when you can expect to see more vibrant red and orange foliage appear.
Certain Fertilizers Can Promote Red Growth In Japanese Maples
While fully mature Japanese maple trees do not usually need fertilizer (since their root systems should be sufficiently developed by that point to take in plenty of nutrients on their own) in some cases the use of fertilizer can help promote more robust growth and development in your trees.
In the case of Japanese maples, it’s important to make sure you select an appropriately balanced fertilizer that contains all the important nutrients they need to remain healthy.
As discussed earlier, if your Japanese maple trees are not getting enough of key nutrients such as nitrogen and manganese, it could impact their overall health as well as their coloring. As such, it could be said that using proper fertilizers to keep your tree healthy can, by extension, also help promote that vivid red coloring which Japanese maple trees are known for.
If you are in the market for effective and well-balanced fertilizers for Japanese maple trees, consider purchasing products such as FoxFarm Happy Frog Japanese Maple Fertilizer or TreeHelp Premium Fertilizer for Japanese Maples. You might also consider consulting with a botanist who is knowledgeable about Japanese maples since they should be able to offer you further recommendations for the care of your trees.
Quick Recap
And there we have it!
To summarize:
- Not all Japanese maple trees begin with red foliage; some begin with green leaves and only turn red in autumn, while other cultivars never turn red at all
- In most cases, it is colder temperatures and shorter days that will trigger the color change from green to red; these conditions usually occur in fall or winter
- The color change itself relates to the breakdown of the chlorophyll in the tree’s leaves, which leaves the brighter anthocyanins and carotenoids as the remaining visible pigments
- Other triggers for a color change include certain types of damage as well as various nutrient deficiencies; since these types of color changes indicate that your tree is unwell, you should take steps to avoid them
- When fertilizing your Japanese maple trees, it’s important to use a well-balanced fertilizer to ensure that your trees are getting all the key nutrients they need to remain healthy
- When in doubt about the state of your Japanese maple tree, don’t hesitate to consult with an arborist, botanist, or Japanese maple tree specialist
If you would like to know more about what is involved with growing Japanese maple trees, books such as Japanese Maples: The Complete Guide to Selection and Cultivation can be an excellent resource.
You might also consider reaching out to an arborist who specializes in Japanese maple trees; they will be able to offer you reliable insight into all manner of things related to Japanese maple care, from watering to fertilizing to pruning.
References:
Deal, D. L., J. C. Raulston, and L. E. Hinesley. “Leaf color retention, dark respiration, and growth of red-leafed Japanese maples under high night temperatures.” Journal of the American Society for Horticultural Science 115.1 (1990): 135-140.
Douglas, Sharon M. “Verticillium wilt of ornamental trees and shrubs.” The Connecticut Agricultural Experiment Station (2008)
Hansen, Sheriden M., Jaydee Gunnell, and Andra Emmertson. “Maples in the Landscape.” (2021): 1.
Niemiera, A. X. (2009). Japanese maple. Virginia Cooperative Extension.
Phillips, G. (2003, December 17). Culture and propagation of Japanese maple. VTechWorks Home.
Schmitzer, Valentina, et al. “Phase change modifies anthocyanin synthesis in Acer palmatum Thunb.(Japanese maple) cultivars.” Acta physiologiae plantarum 31.2 (2009): 415-418.
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