Avocado trees are a subtropical evergreen tree that produce highly sought-after avocados and are commonly found in Brazil, Mexico, and California. People who grow and own avocado trees not only enjoy their delicious avocados, but they also get a quaint, picturesque look for their yards. But one of the interesting things about avocado trees is their tendency to drop their leaves. But why do they do this?
Botanists explain that avocado trees will periodically drop their leaves in order to reduce the number of leaves they must support. For example, the weight of a single leaf can be significant when taken into the consideration the amount of leaves supported by a single branch. In addition, the leaves of an avocado tree are typically larger than most perennial trees because of their need to photosynthesize more nutrient-rich soil present in tropical climates. This additional weight can cause a branch to split or crack, and when this happens to a branch, the entire branch can be damaged and can sometimes cause the entire tree to become unproductive. It is believed that the leaves are dropped in order to help protect the tree from potential damage.
Experts also suggest that the dropping of the leaves is an act of survival for the tree. When temperatures begin to drop in the winter months, the leaves of the avocado tree can drop in order to help the tree withstand the cold temperatures. In addition, by allowing the leaves to drop, the tree preserves more energy for use during times of colder temperatures. This energy is able to help the tree produce better quality fruit, even in times of extreme cold, and sustains the tree from damage from the cold winter temperatures.
In addition to helping the tree to survive cold temperatures, the dropping of the leaves also allows the tree to focus its energy on the production of fruit rather than on leaves. While some trees may continue to produce leaves throughout the better part of the growing season, an avocado tree will focus more of its energy on the production of quality fruit. In addition, many varieties of avocados are semi-dwarfing, meaning they don’t grow to an enormous size, so they don’t need as many leaves in order to conduct photosynthesis.
Overall, the reasons why avocado trees drop their leaves may seem mysterious, but are actually quite understandable. It is an act of survival for the tree, helping it remain healthy and productive in the face of cold weather and too many growing leaves.
Climate
Avocado trees thrive in subtropical climates and can tolerate frosts from time to time. Generally, the average temperature should be between 15-20 degrees Celsius for the tree to thrive and to keep its leaves. However, temperatures slightly higher than 20 Celsius tend to increase the risk of leaf loss in avocado trees as the high temperatures can put a strain on the tree, leading to excessive shedding of its leaves.
Certain locations around the world favour the growth and long-term sustainability of avocado trees. For example, parts of Africa, Mexico, Peru, Colombia and India are known to provide optimal conditions for the growth of avocado trees. In such areas, which tend to experience consistently high levels of humidity, the leaves and branches of the tree can remain healthy, therefore reducing the chances of leaf-fall.
The condition of the soil also plays an important role in determining how well an avocado tree can do. Avocado trees require nutrient-rich soil for growth and production, and if the soil is too acidic or too alkaline, it can stunt the growth of an avocado tree, leading to the shedding of its leaves. Also, if the soil contains insufficient amounts of essential minerals such as magnesium, an avocado tree can lose its leaves.
Last but not least, proper maintenance and gardening practices can prevent the excessive shedding of leaves in an avocado tree. Trees need to be adequately watered, fed and pruned in order to remain healthy and overflowing with vibrant green leaves.
Pests and Diseases
Avocado trees are often affected by certain pest infestations. These pests can cause an avocado tree to drop its leaves as a result of damage to its leaves, branches and roots. Common pests include aphids, scale insects, beetles, mites, thrips and caterpillars, which are known to feed on an avocado tree’s foliage, leading to a decrease in the tree’s ability to produce healthy leaves.
Aside from pests, certain diseases can also cause an avocado tree to lose its leaves. These diseases include root rot, leaf spot, powdery mildew and tomato ringspot virus. Of these, root rot is particularly important to detect as it can kill an avocado tree within weeks if left untreated. Generally, root rot is caused by excessive moisture and over-fertilization and can be identified by yellowing and wilting of the leaves.
Certain tree diseases such as these may be difficult to detect, but signs of illness can be identified through a careful observation of the leaves. For instance, yellowing and discoloration can indicate a severe tree disease, while curled and wilting leaves can be indicative of pests and drought stress.
Therefore, when attempting to gain insight as to why an avocado tree is dropping its leaves, it is important to identify if the cause is a pest or a disease. In such cases, it is necessary to consult a qualified horticulturist in order to provide a reliable diagnosis that can help to bring the tree back to health.
Nutrition
Leaf drop in an avocado tree can also be caused by a deficiency in certain nutrients. A good quality mixture of well-rotted compost, animal manure, peat moss or leaves should be used in order to supply the tree with a balanced supply of nutrients, catalyzing its growth and productivity.
Avocado trees need an ample supply of nitrogen, in order to produce healthy and ample foliage. Nitrogen can be applied by adding animal manures or purchasing fertilizers prone to breaking down slowly such as slow-release fertilizers.
Furthermore, the leaves of an avocado tree can be prone to suffering from chlorosis, which is caused by an insufficient amount of iron in the soil. Iron deficiency can be fixed using organically-approved products usually containing iron sulfates, which should be applied to the soil without fail every few months throughout the season.
Generally, a wide range of pests, diseases and nutrient deficiencies can cause an avocado tree to lose its leaves. Understanding and identifying the cause is essential to preserving the health and longevity of an avocado tree.
Pruning
Lastly, the pruning of an avocado tree should be done with care in order to prevent it from dropping its leaves. Pruning an avocado tree properly can help to keep it healthy by eliminating dead, damaged or diseased branches or leaves.
It is also necessary to prune an avocado tree every few years in order to maintain its shape, increase its vigour and allow it to produce more flowers and fruits. Pruning will also deter pests and diseases from the tree, while cutting out any dead or ill branches will reduce the stress they may place on the tree and increase air circulation.
In addition, when pruning an avocado tree, it is important not to cut too much or too often, as this can cause the tree to go into shock and can lead to the loss of its leaves. If the tree is left unpruned for too long, however, it can become overgrown, leading to greater difficulties when the time does come to prune it.
Thus, proper pruning of an avocado tree is of utmost importance when it comes to preserving the health of the tree and to prevent it from shedding its leaves.
