I absolutely love when leaves change in the fall. It is a somewhat bittersweet thing, of course, because it means Old Man Winter is lurking around the corner and I need to dust off my snow plow, etc. However, my thoughts on winter is another matter, because what I want to talk about is why leaves change.
Recently, I stumbled across a great article, so a lot of what I am going to take about is based off of it. So why does a leaf change color? It is all about chlorophyll, which gives leaves their green color. During the warm months, though, leaves are constantly losing their chlorophyll. This process accelerates as the nights turn colder.
In the best of conditions, trees are able to reabsorb nitrogen in the structure of their pigment molecules. You get color, then, when some carotenoid pigments are retained even after the chlorophyll has been removed. Specifically, you get yellow leaves with this process.
Why do leaves change to a red color?
When leaves change into a red color, which of course is most people’s favorite color, a slightly different process takes place. In these cases, active synthesis of anthocyanin pigments has taken place. Red leaves, then, result from a delicate balance of anthocyanin and carotenoids and possibly a little bit of chlorophyll left over.
Anthocyanin and chlorophyll result in brownish colors, while anthocyanins and carotenoids produce orange hues. In some trees, the colors can be uniform in appearance, whereas individual trees can features leaves that vary somewhat significantly from one another. Some individual leaves can possess red, yellow and orange.
In some cases, though, green will remain in some leaves. Why is that? Stay tuned for our next blog! Have questions about anything or need help cleaning up this fall, call Heidelberg Farms at (603) 501-9919. We are always happy to just answer questions, too.