If you live in the southern tip of the United States or further south, you have the unique opportunity to grow an avocado tree outdoors in your garden. These tall, evergreen fruit trees are best known for their creamy fruits with abundant health benefits. The tree’s thick, bright green foliage is also grown for its ornamental value. However, it is important to keep in mind that all parts of this tree, including the fruit, are toxic to a wide range of animals .
|Common Name||Avocado Tree|
|Botanical Name||Persea americana|
|Plant Type||Tree, Fruit|
|Mature Size||60 ft. tall, 30 ft. wide|
|Sun Exposure||Full, Partial|
|Soil Type||Loamy, Sandy, Well-drained|
|Soil pH||Acidic, Neutral|
|Bloom Time||Late Winter, Spring, Early Summer|
|Flower Color||Yellow, Green|
|Hardiness Zones||9-11, USA|
|Native Area||North America, Central America, Asia|
|Toxicity||Toxic to pets|
How to Plant an Avocado Tree
It is best to plant avocado trees outdoors in the spring. This allows the tree ample time to become established before cooler, winter temperatures arrive. This is especially important in the northern areas of the avocado tree’s hardiness zones. Choose a planting location that provides ample room for these tall trees to grow. Plant them at least 10 feet away from structures and allow for at least 30 feet in between each avocado tree, if you’re planting more than one.
Keep in mind that the root system of avocado trees is quite sensitive, so try not to unnecessarily disturb the roots during the planting process. Dig a hole that is wider than the root structure. The depth of the hole should generally match the height of the root ball, since planting the tree too deep or too shallow can cause problems.
The trees are vulnerable to high winds so very young, soft, and immature trees may benefit from support. Choosing a planting location that offers wind protection will help keep your tree upright and healthy. Just be sure the your tree receives plenty of sunlight and has well-draining soil. If soil conditions are less than ideal, amend the soil with sand or another well-draining substrate before planting. Avocado trees can also be grown in a container, though this will eventually stunt their growth.
Avocado Tree Care
Like most tropical plants, the avocado tree thrives on a lot of sunshine. Plant this tree in a location where it can receive at least 8 hours of sunlight every day. These trees can tolerate partial shade, but grow best and produce more fruits when kept in full sun.
Avocado trees prefer rich, loamy, and well-draining soil. It is important that the soil is aerated and does not hold onto excess water, as soggy soil can lead to root rot. A soil pH that is acidic to neutral, between 5 and 7, is ideal. These trees are sensitive to alkaline soil.
Adding a layer of mulch around the tree can help the soil retain the right amount of moisture and will offer protection to the avocado tree's shallow root system. Be sure to keep the mulch about 6 inches away from the base of the trunk to avoid suffocating the roots or causing collar rot.
Avocado trees benefit from infrequent, deep watering. This encourages deeper, stronger root growth. Wait until the soil begins to dry out, then water deeply. During the summer months when temperatures are hot and conditions may be dry, the avocado tree will require more frequent watering. Young trees also require more frequent watering as the tree establishes. Mature trees should receive around 2 inches of water per week.
Temperature and Humidity
These famous fruit trees can only be grown outdoors in USDA hardiness zones 9-11, limiting them to tropical and subtropical climates, unless you decide to grow an avocado tree indoors. They are frost-sensitive and grow best in temperatures between 50 and 85 degrees Fahrenheit.
Fertilizing an avocado tree during the growing months will help encourage healthy growth and fruit production. Start in the late winter to early spring and feed until the fall, depending on the specific instructions included with your chosen fertilizer. Nitrogen is important for this tree, so be sure the fertilizer you choose has high amounts of nitrogen. Fertilizers specifically designed for avocado or citrus trees work well.
Pollinating an avocado tree can be a bit tricky. These trees have what are called ‘perfect’ flowers, which means each flower has both female and male parts. However, avocado tree flowers open their female and male parts at separate times, making self-pollination possible but not always as fruitful. For optimum pollination, it is ideal to have two avocado trees.
Avocado trees are considered either type A or type B. Type A trees open their female parts in the morning of the first day and their male parts in the afternoon of the second day. Type B trees open their female parts in the afternoon of the first day and their male parts in the morning of the second day. These different times make cross-pollination possible between the two types. When choosing which trees to plant, be sure you have both type A and type B for the best results.
Types of Avocado Trees
All avocado trees stem from three main varieties: Mexican, West Indian, and Guatemalan. Within these categories, there are several avocado varieties available.
- Hass: One of the most popular avocado varieties, the Hass avocado is often found in grocery stores. It is a hybrid of Guatemalan and Mexican avocado varieties. This is a type A tree that produces thick, bumpy-skinned, rich, and creamy fruits. It is more sensitive to heat than other varieties. Hass avocado trees are known to produce a reasonably sized yield when grown on their own.
- Fuerte: Also a widely known avocado type, the Fuerte avocado is a type B tree often grown with Hass avocados. This variety is also a hybrid between Guatemalan and Mexican varieties. These trees produce large, oval-shaped fruits with relatively smooth, thin skin that peels away easily. The fruits have less oil content than Hass avocados. These trees are also more sensitive to heat, making them a good fit for the northern borders of the avocado's growing zones.
- Pinkerton: This type A, Guatemalan tree is popular for its smaller size and large fruit yield. It produces oblong fruits with flesh similar to the Hass avocado—rich and creamy. These trees require a type B avocado tree to produce a significant fruit yield.
Harvesting homegrown avocados is satisfying since a good amount of time and patience goes into growing these creamy fruits. For nursery-bought trees, you can expect to see fruit in three to four years. For avocados started from seed, it may take five to 13 years before fruits appear.
When fruits appear, wait until the avocado grows to its mature size. The fruits do not ripen on the tree, so avocados are picked as soon as they are full size. Bring the avocados indoors and let them rest on a counter until ripe. Give the avocado a gentle squeeze to test for softness. Once the flesh is soft but not squishy, it is time to enjoy the fruits of your hard work.
How to Grow Avocado Trees in Pots
Though they will not reach their full height, avocado trees can be kept in containers. This is ideal for small yards or gardens near the northern edge of the avocado’s growing zones, as potted trees can be moved to a protected area when cold weather arrives.
Young trees or dwarf varieties are ideal as these will stay small for some time. When choosing a container, be sure it drains well and has unobstructed drainage holes. Breathable materials such as terra cotta make a great choice, as water and air can freely move through the container. Fill the container with well-draining soil, such as compost and sand.
Pruning avocado trees will encourage more manageable, bushy growth. It is best to start when trees are young. If grown from seed, start pruning when the seedling is only 6 inches tall, snipping off the top pair of the leaves. When it reaches a foot in height, trim back 6 inches. After this, prune the tree yearly.
Mature trees require occasional pruning to keep the tree clean and to create adequate space for air and light to travel through. Light pruning can be done any time of year, though heavy pruning should be done in the early spring. Prune away any low-hanging branches to keep the tree clean and accessible. Prune thick areas to ensure adequate light and airflow. Cut back any dead wood and trim away V-shaped branches. Continue to prune the tips off the brranches if you decide to keep the tree on the smaller side. Remember, start slowly and do not take off more than one-third of the length of each branch.
Propagating Avocado Trees
Propagation is often done through grafting, layering, or cuttings. It is best to propagate in the spring when new growth is abundant. Grafting is often done to combine the desirable qualities of two different varieties of avocados while layering and starting cuttings are done to produce duplicate trees. Here’s how to perform each method of propagation:
You will need sharp snips, moist and well-draining potting soil, a small pot, and IBA rooting hormone.
- In the spring, select new growth that is 5 to 6 inches long and has several leaves that have not opened.
- Using sharp snips, cut the new growth branch at a 45-degree angle.
- Wound the cut end by scraping at the bark on either side of the cutting. This will encourage root production.
- Dip the cutting into IBA rooting hormone.
- Bury the cut end into moist, well-draining soil.
- Keep the soil moist and place the cutting in a sunny area.
- After a couple of weeks, gently tug the cutting to check for resistance, which indicates root growth. Repot the cutting into a larger pot or outdoors.
You will need sharp snips, a sharp knife, and something to cover the grafted area, such as grafting tape.
- Follow steps 1 and 2 as if you are taking a cutting.
- Remove the tip of the cutting, along with any leaves that are present.
- Then, wound the tree you would like to graft onto by removing a section of bark.
- Make sure the cambium of the cutting and the cambium of the tree are touching.
- Secure the cutting onto the tree, making sure to cover the exposed areas.
- In a few weeks, the grafted branch and the main tree should be fused together.
You will need a sharp knife, a rooting medium that can be wrapped around a branch, and rope or tape to secure the rooting medium around the tree.
- Select the branch you would like to take as a new tree.
- Using a clean knife, cut two circles around the branch to create a section of bark that can be peeled away.
- Once the bark is removed, scrape the inner branch to clean the cambium away.
- Wrap the exposed inner branch with rooting material, such as compost in a small bag (make sure the compost is wrapping the branch, not the bag) or another rooting medium. Secure around the branch.
- In several weeks, roots should develop. When this occurs, cut the branch off below the formed roots and plant the new tree.
How to Grow Avocado Trees From Seed
Starting avocado trees from seed is a fun, simple project. However, it is important to keep in mind that seeds will not produce trees identical to the parent tree. To do this, you will need an avocado seed, a jar of water, toothpicks, a sharp knife, a small pot, and well-draining potting soil. Then follow these instructions:
- Using a sharp knife, poke three or four holes around the circumference of the avocado seed.
- Poke the toothpicks into the holes. This will create the supports needed to suspend the seed in water.
- Submerge the thick, or bottom end, of the seed into the water. Around one-third of the seed should be in the water.
- Place the seed in a sunny location and change the water daily.
- After a few weeks, roots should form and leaves should appear at the top of the seed.
- Once this occurs, gently plant the seed in well-draining soil.
When grown in the appropriate zones, avocado trees do not require extra care during the winter. For trees grown on the northern edges of their growing zones, it is best to keep them in pots so they can be moved indoors or to an area protected from cold weather.
Common Pests and Plant Diseases
Common pests that may bother an avocado tree include mites, caterpillars, borers, lace bugs, and thrips. Diseases include root rot, fruit rot, sun blotch, and cankers. Be alert to the presence of these pests or early signs of disease. Prompt action is the best way to remedy any developing problems before they threaten the health of your avocado tree.
Are avocado trees easy to grow?
Though avocado trees are not quick to produce fruits, growing the tree for ornamental value is easy—assuming you’re growing the tree within its growing zones.
Do you need two avocado trees to produce fruit?
While some avocado trees are self-fruiting, such as the Hass avocado, these trees will always produce a larger yield of fruit if two are grown near each other. Be sure you plant a type A and a type B avocado tree for the best results.
What is the lifespan of an avocado tree?
The lifespan of an avocado tree will depend on its environment. However, healthy avocado trees have been known to live for hundreds of years. Some have even been reported to live up to 400 years old.
“The Scoop on Avocado and Your Pets.” ASPCA, https://www.aspca.org/news/scoop-avocado-and-your-pets