Yellow Hosta Leaves – Why Are They Turning Yellow?
Hostas are native to Mediterranean region. However, they have been cultivated in many parts of the world including India, China, Japan and Korea. Most commonly known as tea plants, these plant produce small greenish-yellow flowers that are used in teas. The leaves of the hosta are also edible and used in salads or soups.
The leaves of the hosta are called “hosta” because they resemble those of a sweet potato. The leaves contain a large amount of chlorophyll which gives them their bright color. Chlorophyll absorbs sunlight energy and converts it into chemical reactions that create sugars and other compounds that make up carbohydrates (the basic building blocks of life). When exposed to air, the chlorophyll breaks down producing free radicals that damage cells.
Free radicals cause cell death. Some of the effects of free radical damage include:
Damage to DNA causing cancer
Inflammation resulting in pain and swelling in joints and muscles
Tumors forming in organs such as the liver, pancreas, stomach, lungs and brain. These tumors may not become life threatening but they can lead to organ failure if left untreated.
Free radicals are created when our bodies use oxygen to generate energy. When we exercise, our bodies use more oxygen and generate more free radicals causing more cell death and damage. The human body has natural defenses against the cell death caused by free radicals. These defenses include:
Antioxidants (vitamins A, C and E) help prevent a wide variety of diseases including cancer and heart disease.
Glutathione is one of the body’s natural antioxidants that helps prevent cell death. It neutralizes the free radicals and allows cells to survive.
The use of exogenous antioxidants, like taking vitamins, helps our bodies replenish the ones we use up and the ones we do not get in our diets.
It is important to note that free radicals are not always “bad.” Our bodies produce them to help fight off infection. Without free radicals, we would have no immune system at all. However, too many free radicals can cause significant damage to the body.
This is why it is important to eat a well-balanced diet, get enough rest and exercise to keep our bodies in good physical shape.
Anatomy of a Hosta Leaf
The leaf of the hosta (like the leaves of all plants) is involved in the process of photosynthesis. Within the leaf, chlorophyll and other chemicals are involved in absorbing sunlight and converting it into sugars and other nutrients. The leaf also has veins that bring the sugars and nutrients to different parts of the leaf.
As we discussed earlier, the chlorophyll breaks down when the leaf is exposed to air. The veins are no exception. When the green color starts to disappear, what is left behind is the vein structure of the leaf. This is what makes the leaf so interesting.
The patterns of the veins are still visible but they will be a different color than the rest of the leaf.
The Hosta Society has divided the veins into three categories: major, minor and reticular. The major veins are the ones that are easiest to see and are closest to the edge of the leaf. These are the veins that are closest to the surface of the leaf and therefore are the first ones to turn color, hence they are the first veins to disappear.
The minor veins run between the major veins. They are smaller and therefore take longer to disappear. The reticular veins are even more difficult to see. Under a magnifying glass, it looks like there are “thousands of tiny spiders webs” all over the leaf.
These tiny veinlets get lost during the fading process.
Major veins Minor veins Reticular veins
When the major and minor veins disappear, what is left are the veinlets. These tiny veins are so small they are hardly visible to the naked eye. They are the last part of the leaf to disappear. Sometimes these tiny veins are still visible on a hosta that has been painted solid green!
At the same time that the veins are disappearing, the rest of the leaf is also thinning. This causes the entire leaf to turn translucent and finally disappear. It looks as if the vein structure is still there. The only thing that is left is a beautiful work of art that has been hidden in plain sight!
History of Fading
Research has shown that Hosta leaves have been used for centuries in the creation of paintings. It was once thought that the leaves were simply painted over because artwork took so long to complete. However, it has since been discovered that many of these paintings were, in fact, a part of the original work!
The first record of this “fading” process comes from an Italian artist by the name of Donato Bramante. He created a fresco for the Vatican called “The School of Athens”. The fresco was completed in 1510. In the fresco are two men that seem to be transparent!
Bramante’s “School of Athens”
The two figures in question can be seen kneeling next to the central figure (the philosopher holding a book). These figures are Niccolò Perotti and Angelo Donnini. They were both students of the great artist and were made transparent to symbolize their lack of knowledge.
In the 16th century, it was customary to destroy artwork that someone else had worked on. It is believed that Niccolò and Angelo’s rival, Raphael, painted them as ghosts to symbolize that they would always be in his shadow.
The Hosta Leaf in Artwork
The next time period that mentions “fading” is during the Dutch Golden Age. There are many paintings from this era that have a “faded” look to them. It is believed that artists such as Van Gogh, Vermeer and Jan Steen used the natural fading process of the hosta leaf to help them create this look.
“A Girl and Her Cat” by Jean Auguste Dominique Ingres
An example of this would be Jean Auguste Dominique Ingres’ painting “A Girl and Her Cat”. Done in 1814, it is believed that he used the natural fading process of the hosta to give the appearance that the young girl and her cat are almost ghosts.
“A Girl and Her Cat” close up
Other colors have been used as well such as blue. There is an unfinished painting by Vermeer called “The Blue Boy”. It seems strange that such care would go into a piece and then not be finished. It is more likely that he created the piece this way on purpose.
In the 1700’s, artists were starting to hide images in their work. This was done by making sections of the painting look faded or “ghosted”. It seems that the artist would often times paint these sections first and then go back to add other things on top of them. When viewed from a distance they would blend in with the rest of the painting.
These “ghosted” sections could contain anything from patriotic symbols to political statements.
There are many paintings that have these “ghosted” sections. In fact, they can be found in artwork as far back as the 1400’s! The most popular location for these hidden images is the groin area of males. It seems that they liked to hide phallic symbols there.
This is where the term “penis graffiti” comes from.
A section of “The Blue Boy” made to look faded
One of the most famous “penis graffiti” paintings is the “Mona Lisa”. It has been determined that there are three hidden images within the painting. The one that is most talked about is one located in the right side of her neck. If you look closely, you can see a pagan goddess!
The next step in the process of hiding images was to use chemicals. Natural ones such as lemon juice or smoke were used. By applying these to the painting, the artist could make certain sections look older than others. It is then up to the viewer to put the pieces together.
The next method used was watercolor paintings on top of the original artwork. This is similar to the watercolor paintings done on parchment that can be seen in museums today. The artist would create the images they wanted followed by applying a clear layer over the whole thing. The clear layer would protect the painting, while making the image underneath transparent.
A watercolor painting on top of another painting
When viewed from afar, the original painting would show through. This allowed for great detail to be added without harming the original work. If done correctly, the artist would only have to show the sections that they wanted to stand out in a different way.
The last method used in hiding images was by using projections. These could be anything from the artist using a camera to take a picture and project it onto the painting to using chemicals that change color depending on the angle you are viewing it from.
A current technology that is being used involves using a projector and a camera to capture your image. The image is then projected back onto a blank canvas. Using chemicals similar to those found in “color-changing” mugs, the painting changes colors based on the angle you are looking at it from.
A projected image
Now that you have an idea of how artwork was created and hidden images were found, let’s get started!
The first one has already been done for you. All you need to do is go to the location and look at the painting. Here is a hint: It is in a place that people visit every day. Good luck!
Note: This challenge can only be completed once.
Sources & references used in this article:
Hosta plant named ‘Paradise Island’ by M Fransen – US Patent App. 12/231,486, 2010 – Google Patents
Hosta plant namedAristocrat by CH Falstad III – US Patent App. 09/076,084, 2000 – Google Patents
Hosta plant’Morning Light’ by G van Eijk Bos, D Van Erven – US Patent App. 09/921,934, 2002 – Google Patents
Hosta plant named ‘Hanky Panky’ by HA Hansen – US Patent App. 10/995,681, 2006 – Google Patents
Hosta plant named ‘Liberty’ by JL Machen Jr – US Patent App. 09/442,325, 2002 – Google Patents
Hosta plant named ‘Pocketful of Sunshine’ by A Bergeron – US Patent App. 13/200,452, 2013 – Google Patents
Hosta plant named ‘First Blush’ by RM Solberg – US Patent App. 14/998,503, 2018 – Google Patents