Mineral Deficiency
A mineral deficiency can cause the leaves of an avocado tree to turn brown. Avocado trees need iron, zinc, magnesium, phosphorus, potassium and nitrogen to thrive. A deficiency of these can cause the leaves to turn brown. Testing your soil and applying the correct fertilizer can help your avocado tree thrive and produce fruit.
Excessive Salt
Applying fertilizer incorrectly and improper watering methods can cause the soil your tree is growing in to have an excessive amount of salt. A very simple, yet highly effective method of removing excess salt from the soil is to let a trickle of water flow from a hose placed near the tree or 24 hours. This should be done about every four weeks during the summer. This is not to be your routine method of watering your tree. Your regular watering routine should be that you water the tree when the top two inches of the soil is dry. The best method for watering is a hose, placed near the tree, running at a slow trickle for about 2 hours.
Finding the Balance for Optimum Growing Conditions
When you begin reading about how to care for an avocado tree, some of the information may seem confusing. You’ll read that the tree needs sunlight and grows best in full sun, but it can also tolerate partial shade during the day. Balance is the key to growing an avocado tree. The following tips can help you find that balance.
- The tree grows and produces the best blossoms and fruit planted in a sunny location.
- Good drainage is essential, yet soil should not be overly dry.
- Mulch can help retain moisture, but keep mulch about 12 inches from the base of the tree to prevent disease.
Cold Weather
Harsh weather conditions such as frost can cause avocado tree leaves to turn brown. The USDA hardiness zones 9 to 11 are the optimum zones for growing avocado trees.If the tree suffers damage over winter and leaves and branches brown, wait until spring to prune any damage. Many time new growth will sprout from what looks like a brown and dead branch.
