Why Are My Avocado Tree Leaves Turning Brown

Environmental Stressors

Avocado trees are sensitive to environmental stresses, including heat and/or cold, inadequate or excessive moisture, and improper soil. When leaves turn brown, it’s often an indication that one or more of these environmental stressors is present. Unexpected changes in temperature and water availability can be particularly damaging. According to the California Avocado Commission, even a slight imbalance in irrigation can cause leaf browning, while prolonged dry conditions can make leaves brown, curl, and drop. Cold damage can also result in curled, brown leaves when temperatures fall too low for the tree’s health.

Operator Error

More often than not, it’s not the environment that causes the leaves to turn brown, but the gardener. Too much water, too little water, or the wrong fertilizer can all cause discoloration in the leaves of an avocado tree. Even when a gardener does everything right, brown leaves may still appear, however in this case it may be due to mechanical damage. The California Avocado Commission suggests checking for signs of mechanical damage from gardeners, animals, or machines, as well as examining the leaves for signs of disease or pest infestation.

Nutrient Imbalance

Nutrient imbalances can also cause the leaves of an avocado tree to turn brown. According to the University of California Cooperative Extension, the most common nutrient imbalance is a lack of nitrogen. Nitrogen is essential to healthy leaf growth and a lack of it will cause leaves to turn yellow and then brown. Fortunately, nitrogen deficiency can be remedied with regular applications of nitrogen fertilizer. Low phosphorus or potassium levels can also cause discoloration, however this problem tends to occur when the gardener is applying too much or the wrong kind of fertilizer.

Pest Damage

Pests such as mites, scale, and whiteflies can cause discoloration in avocado tree leaves. These pests suck the life from the leaves, causing them to become pale and later, brown. The damage from these pests can be severe, so it’s important to take action quickly. The University of California Cooperative Extension recommends monitoring the tree for signs of pest damage and treating the tree with an appropriate pesticide as soon as possible.

Fungal Disease

Fungal diseases can cause brown leaves on an avocado tree. According to the University of California Cooperative Extension, brown spots and yellow or brown discoloration are often telltale signs of a fungal disease. The best way to treat a fungal disease is to prune away infected branches and treat the remaining tree with a fungicide.


Waterlogging – the condition where an excess amount of water is present in the soil – can also cause Brown leaves on an avocado tree. Waterlogging can be caused by a variety of factors, including improper irrigation and poor soil drainage. The symptoms of waterlogging can vary, however the most common ones are yellow, drooping leaves and root rot. Fortunately, it’s possible to mitigate waterlogging by improving the soil and adjusting the irrigation regimen.


Avocado trees need a lot of light in order to thrive and if the tree is not getting enough light, the leaves can become pale or brown. According to the California Avocado Commission, avocado trees need full sun and should be planted in an area where they will get six or more hours of direct sunlight per day. If the tree is planted in an area that is too shady, the leaves will begin to brown as the lack of light takes its toll.


Inadequate soil is also a common cause of leaf browning in avocado trees. Poor soil can lead to shallow root growth, which can in turn lead to a lack of nutrients, water, and air. The symptoms of poor soil include dropping leaves, yellowing, and leaf burn. The University of California Cooperative Extension recommends improving the quality of soil by adding compost and natural fertilizers.

Root Rot

Root rot is a fungal disease that affects the roots of avocado trees. The symptoms of root rot include wilting and yellowing leaves, as well as browning branches and roots. Root rot can be caused by a variety of environmental conditions, including overwatering and poor drainage. When root rot is present, it is important to prune away the affected branches and roots and to treat the tree with a fungicide. It is also important to improve the soil and adjust the irrigation routine.


Avocado trees require a lot of water to stay healthy and if the tree is not getting enough water, the leaves may begin to show signs of stress such as browning and drooping. Drought conditions can also cause the leaves to drop prematurely, as well as stunting the growth of the tree. To mitigate the effects of drought, the California Avocado Commission suggests irrigating the tree regularly and deeply.


As important as it is to keep an avocado tree adequately watered, it is also important to make sure you are not overwatering. Overwatering can cause root rot, an excessive amount of water in the soil, as well as leaf browning. To prevent overwatering, it is important to monitor the soil moisture levels and to avoid overwatering the tree.

Gordon Wesson is an environmentalist and author who lives in the Pacific Northwest. He has been writing for many years about topics related to trees, the environment, and sustainability. In particular, he is passionate about educating people on the importance of living in harmony with the environment and preserving natural spaces. He often speaks at conferences and events around the country to share his knowledge with others. His dedication to protecting our planet makes him one of the leading voices in his field today.

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