Fall is a time of year when we are graced with an abundance of beautiful colors. The leaves on apple trees become vibrant red, yellow and orange hues, making for a magnificent display of color. While the color of the leaves is one of the most viewed events during the fall season, the actual process and timing of the leaves falling from the tree can be a mystery.
When you hear the phrase “falling leaves”, you likely think of autumn. This is because leaves typically begin turning colors and falling in the late summer and early fall. Depending on the climate, apple tree leaves can start to fall anytime from late August to October. While some areas may experience their leaves turning colors and falling in late summer, other regions may have a longer window of time for the leaves to shower down from the trees.
The process of apple leaves falling from a tree can be broken down into 3 distinct stages. First, healthy leaves will enter the abscission stage, where the stem of the leaf begins to deteriorate and results in the leaf eventually falling off the tree. After the abscission stage, the leaves first enter a “climacteric” stage where they appear to be holding onto the tree before finally entering the senescence stage where the leaves are ready to be let go.
Weather can also play a role in how the leaves change color and how soon they fall. If the climate is warmer and drier, the leaves tend to fall sooner. On the other hand, if the climate is damp or cool then the leaves may take longer to change color and fall from the tree. Additionally, trees located in more urban environments could take longer to drop their leaves because of the increased carbon dioxide, causing the leaves to stay on the tree for an extra week or two.
Timing and weather make up a key relative in the amount of time it takes for apple leaves to fall from the trees. Characteristics of the tree, such as species, age, environment and fertility of the soil, can also influence the lifespan and beauty of the leaves. If the tree is healthy and the climate is ideal, the leaves can last for several weeks, providing the vibrant colors of autumn before they eventually finish their descent.
A Look at Different Varieties of Apple Trees
One of the factors that determines when apple tree leaves fall is the type of tree. By examining a few different varieties of apple trees and their unique attributes, we can better understand the timing of the leaves’ life cycle. Trees such as the Sansa apple tree, known for its unique reddish-orange hue, tend to lose their leaves sooner than other apple trees, with many of the leaves falling off at the end of September. On the other hand, you have Granny Smith apple trees, which are more accustomed to a more temperate climate, and have a bit more longevity in the lifespan of the leaves. For example, Granny Smith leaves can remain on the trees as late as December due to their hardiness.
Other apple tree varieties, such as the Honeycrisp or Fuji, can remain on the tree anywhere from late October to late November. These varieties are especially known for their vibrant colors, making their transition to fall a breathtaking display to witness.
The Impact of Disease on Apple Tree Leaves
Diseases have the potential to dramatically impact when apple tree leaves fall. One of the most common apple tree diseases is apple scab, a fungal infection that can lead to premature leaf dropping and defoliation. Apple scab is highly active in wetter and cooler climates, making it a more serious problem in the autumn season. Additionally, apple trees can also be affected by cedar apple rust, a type of infection caused by other trees in the forest, making it even more challenging for the apple leaves to remain on the tree.
Apple scab and cedar apple rust make it increasingly harder for apple tree leaves to stay attached to the tree as the leaves can become discolored and deformed, making it easier for the leaves to be released early. Additionally, trees affected by apple scab or cedar apple rust are likely to experience a heightened intensity of leaf dropping and are thus likely to enter the senescence stage much sooner. Because of this, apple tree leaves with any infection tend to fall significantly sooner than other healthy trees.
How the Winter Season Affects the Leaves
Apple tree leaves usually remain on the tree until late autumn, but winter can also play a factor in when the leaves decide to let go. If the climate is cooler and wetter, the leaves can become trapped inside a layer of frost. This frost layer can make it increasingly hard for the leaves to be released from the tree and can thus extend their lifespan. On the other hand, if the winter season is colder and dryer, without prolonged rainfall, the leaves will often lose their grip and drop from the tree sooner than average.
Besides the weather, apple trees can also become affected by winter weather in the form of snow or cold-damaged. Leaves can become easily damaged if they are constantly exposed to heavy and wet snowfall, as the leaves quickly break-down and are unable to hold onto the tree. Additionally, when exposed to extreme cold, apple tree leaves can begin losing their cells, thus making it much easier for them to be released.
Preventing Early Leaf Falling
Apple trees can experience premature leaf dropping due to a variety of factors. To prevent this from happening, one of the most important things to remember is to routinely inspect and take good care of your trees. Be sure to inspect your trees regularly and take note of any abnormalities or discolorations. Additionally, try to water your trees and keep the soil around the tree well-irrigated, as this can potentially reduce the risk of disease.
In cases where a tree is infected with a disease like apple scab, it’s important to focus on preventative measures. The less contact your trees have with the infection, the less likely they are to experience premature leaf-fall or defoliation. Always wear gloves when handling infected leaves or branches to help prevent the spread of infection. Additionally, it is important to correctly treat the infection and prevent it from continuing. Lastly, regularly pruning the trees can help promote healthier and more structurally sound growth. This can, in turn, help maintain a longer lifespan for the leaves, thus extending the autumn season for at least a few extra weeks.
Seeing Nature’s True Beauty in Autumn
The changing of the leaves from a light to dark green, to hues of red, yellow and orange make for a visual paradise in the autumn season. With apple trees, we experience the range of colors and beauty that the season so easily provides. With an understanding of when apple tree leaves fall, we can better appreciate the beauty that the season brings, while also gaining an appreciation of the natural complexity of the tree’s lifecycle.
