Why Are My Avocado Tree Leaves Changing Color?

If you’re perplexed by the sight of your avocado tree leaves turning brown and aren’t sure what to do, you’ve come to the right place! Avocado trees can experience leaf browning due to various reasons, and in this article, we’ll explore the most common causes as well as some lesser-known factors that could be affecting your avocado tree.

Not Enough Water

Avocado trees have a higher water requirement compared to many other fruit trees. In hot weather, inadequate watering can lead to the leaves turning brown. Avocado trees cool themselves through a process called transpiration, where they release water similar to how our bodies use sweat. Insufficient water supply hinders this cooling process, resulting in brown avocado leaves.

How to Identify it:

Aside from browning, the leaves will appear and feel extremely dry. They may also curl at the edges and eventually fall off.

How to fix it:

Check the moisture level in the soil around your avocado tree by inserting your finger into it. Only water the tree when the top two to four inches of soil are dry. Overwatering can also be problematic, so be careful not to overdo it.

Ensure deep watering so that the moisture penetrates about two feet below the soil surface. In hot weather, monitor the tree more frequently to prevent it from drying out excessively. The soil should be adequately saturated, with a texture similar to a wet sponge when squeezed.

Adding a layer of compost or mulch on top of the soil helps retain moisture. With a two to four-inch layer of mulch or compost, the soil around your avocado tree stays moist for longer periods, reducing the frequency of watering. Moreover, compost and mulch enrich the soil, providing essential nutrients for your avocado tree over time.

Further reading:  10 Unique Plants That Resemble Lavender + Quick Care Tips

Chloride Salt Build-up in the Soil

Another common cause of browning avocado leaves is chloride build-up in the soil. Chloride salt is naturally present in water, including fresh water and purified water. When water evaporates, it leaves behind chloride salt in the soil.

Shallow watering and excessive evaporation in hot weather can lead to an accumulation of sodium chloride in the soil. Avocado trees are more sensitive to chloride compared to other plants. As the roots absorb chloride, it accumulates within the tree over time. When the chloride level becomes too high, it causes the leaves to turn brown and eventually die.

How to Identify it:

Browning avocado tree leaves due to chloride build-up usually begin at the tips. If left untreated, the brown color spreads across the entire leaf, causing it to wither and fall off.

If you’re uncertain whether chloride build-up is the issue, you can obtain a soil salinity test through your local extension office.

How to fix it:

Ensure your avocado tree has proper drainage. If it does, you can flush out excess salt from the soil by providing extra water. Deeply water the avocado tree at least twice a week for several weeks to allow the chloride build-up to leach out of the soil. This is the only effective method to remove chloride accumulation.

For avocado trees without adequate drainage, address the drainage problem first. Frequent and deep watering can lead to root rot if the water is unable to drain effectively.

In the future, water your avocado tree regularly and deeply. This practice helps regularly flush out excess salt, preventing chloride buildup in the soil.

Further reading:  30 Creative Indoor Plant Decor Ideas to Showcase Your Houseplants

Other Causes for Avocado Tree Leaves Turning Brown

In addition to the two most common causes mentioned above, there are several other factors that can contribute to browning avocado leaves. These include sun scorch, very low temperatures or frost, fungal diseases, nutrient deficiencies, pests, and humidity issues.

Sun Scorch:

While avocado tree leaves don’t typically experience sun scorch, it can occur in specific situations. Newly planted young avocado trees, previously grown in shaded nurseries, may undergo a period of shock when exposed to full sun, especially during summer. Providing temporary shade until the tree gets acclimated can be beneficial. Additionally, excessive heat, especially with consecutive days over 100 degrees, can also cause sun scorch. Sufficient watering helps prevent sun scorch issues.

Very Low Temperatures or Frost:

If browning occurs after a frost or a period of very low temperatures, it is likely a reaction to the cold. In such cases, the tree will recover as temperatures rise, so no intervention is necessary.

Fungal Disease:

If your avocado leaves have brown spots instead of overall browning or browning at the tips, it may be due to fungal diseases such as scab, verticillium wilt, or Alternaria. The treatment for each disease depends on its specific characteristics. To learn more about identifying and treating diseased avocado trees, refer to our article on 5 Common Avocado Tree Diseases.

Nutrient Deficiency:

A nutrient deficiency, primarily zinc, nitrogen, or iron, can cause avocado tree leaves to turn brown. A soil test is the most effective way to diagnose nutrient deficiencies. You can obtain a soil test through your local extension office or choose an at-home test available on platforms like Amazon. Once you identify the nutrient deficiency, you can address it by applying appropriate fertilizer or organic matter like compost, based on the soil test results.

Pests:

Pests such as lace bugs and grasshoppers can feed on avocado tree leaves, leading to browning or other issues. If brown spots are accompanied by holes in the leaves, pests may be the cause. For guidance on identifying and treating pests, refer to our post on 6 Common Avocado Tree Pests.

Further reading:  Grow Green and Gold: The Beauty of Chrysogonum Virginianum

Humidity Issues:

In very humid conditions, avocado trees may absorb water faster than they can release it through transpiration. This results in edema, which is the accumulation of water that damages the plant’s cells. Symptoms of edema include brown spots, a crumbly texture, or swollen veins on avocado tree leaves. To address this issue, allow the soil to dry before watering again.

The Most Important Thing to Do for an Avocado Tree with Browning Leaves

While it can be disheartening to see your avocado tree experiencing browning leaves, there is hope. Most problems that cause browning leaves are treatable with proper care and attention. With the right steps, your avocado tree will bounce back and continue to produce healthy fruit.

Check on your Trees Regularly:

Regularly monitoring your avocado tree is essential to catch any problems early. By promptly identifying issues, you can address them before they cause significant damage or spread to other trees.

Wrapping Up Avocado Tree Leaves Changing Color

Avocado tree leaves turning brown can be frustrating, but the good news is that there are usually solutions available. The challenging part is diagnosing the specific problem. Once you identify the cause of browning leaves, you can take appropriate action to resolve it and get back to enjoying the fresh, tasty, and healthy avocados from your tree.

If you’re excited for more avocado-related content, be sure to check out the Ames Farm Center website for additional tips on growing avocados, informative guides, and delicious recipes!

Ames Farm Center

Two avocados growing on a tree.