Growth Habit and Overall Size
Avocado trees have an upright growth habit and can grow to be between 30 and 40 feet tall and about 10 to 25 feet wide. The tree can become a sprawling structure if given enough space, but it usually requires pruning to keep it in shape. The tree’s canopy typically grows from 4 to 5 feet from the trunk, with dense and fine-textured foliage. Avocado fruits generally have a high oil content, and when ripe, their leathery skin turns dark green to purple.
Climate
Avocado trees grow best in warm and sunny areas with a yearly mean temperature of 60 F and very few days of frost. They will not tolerate temperatures below 28 F, so they are commonly grown in tropical or subtropical regions. The trees are most commonly seen growing near Coachella and the Mexican border in Southern California, the Florida Keys and Hawaii.
Soil Requirements
Avocado trees require soil with good drainage and consistent moisture. Loam soils tend to be the most suitable and may contain sand, silt, clay, or any combination thereof. A pH of 6.0 to 6.5 is preferred, which allows the soil to retain and release essential minerals for the tree. Amending the soil with bark mulch or compost before planting can help improve drainage and moisture retention.
Fertilization
Fertilization of the tree is an important consideration for the growth and health of the avocado tree, and beneficial microorganisms can help meet the tree’s nutritional needs. An all-purpose fertilizer may be applied in the spring and should be supplemented with micronutrients like zinc, manganese, iron, and copper. Applying fertilizer according to manufacturer recommendations, and avoiding over-fertilizing, is important to prevent foliage burn.
Water Requirements
Avocado trees need access to plenty of water if they are to remain in good health through periods of dryness. Newly planted trees should be watered regularly for several weeks to ensure that the soil is evenly moist. After the tree is established and the root system is established, watering is still important, especially during dry times. Supplemental watering may be necessary for young trees when rainfall is inadequate.
Pruning
Pruning an avocado tree can help maintain an attractive appearance, ensure good air circulation, and increase fruit production. Pruning should be done while the tree is young, and it should be done carefully to avoid injury or excessive stress. When pruning, young growth should be cut at an angle just above a node or a bud, and large branches should be cut at the trunk and not pulled.
Pest Control
Avocado trees may be susceptible to common pests like mealybugs, aphids, and scale. To help reduce the risk of pest infestation, a good practice is to keep the trunk and branches clean and free of debris. It can also be beneficial to incorporate beneficial insects like ladybugs which feed on pests and to use pesticides sparingly. Professional pest control can be helpful in more serious cases.
Harvest and Storage
Avocados are usually ready for harvest between 8 and 10 months after flowering, albeit this depends on the cultivar. Avocados should be stored at room temperature and used as soon as possible once ripe. Ripe avocados can also be stored in the refrigerator for a few days before consumption.
Propagation
Avocado trees can be propagated from seed, cuttings, or rootstock. Growing an avocado tree from seed can be a fun and educational experience, but it is rarely recommended as the process can take several years. Cuttings and rootstocks tend to be quicker and more successful methods of propagation.
Cold Tolerance
Avocado trees can suffer from both blossom damage and leaf burn typically when temperatures dip below 28F. Certain varieties are more cold tolerant, so it is important for those living in colder climates to select such a cultivar with greater cold tolerance in mind. Protecting the tree with a frost blanket is an additional layer of protection during extreme temperatures.
Pruning Techniques
The main pruning technique used for avocados is called step pruning. We prune in steps as when pruning a single large branch which is thick and wide, the whole branch can be damaged or lost. In step pruning, we cut along the branch in 4-5 steps to avoid a thick, wide cut and to reduce shock to the tree.
Training
Central Leader Training is an approach used to help keep avocado trees under control when the canopy branches are beginning to take up too much space. This method involves pruning and carefully shaping the central leader (trunk) so that the canopy branches have a controlled and compact structure over time.
Maintenance
Avocado trees may need regular maintenance to keep them healthy and productive. Maintaining a clean and weed-free area around the tree can help discourage pest infestations. Good soil health is necessary to ensure the tree’s nutritional needs are met and to ensure adequate drainage, so fertilizing and replenishing the soil can help keep the tree in good condition.
Container Growing
Avocado trees can be grown in containers, which can be beneficial in spaces with limited room. It is important to choose a large container, at least a 3-5 gallon size, and to use a quality potting mix. Regular repotting to keep the tree in a larger container, as the tree and root system grow, is essential. Regular watering is also necessary to ensure good soil moisture, and proper drainage must be maintained.
