The topic of avocado production in Victoria County has become quite popular over the years as improved varieties are being planted here with varying degrees of success. Thanks to Mr. Joe Moore for bringing this well-researched information to our column this week — Matt Bochat, County Extension Agent-Ag/Natural Resources, Victoria County
The avocado tree is of tropical origin in the Western hemisphere. Commercial avocado production in Texas is limited to the Lower Rio Grande Valley area; however, trial and specimen avocados are grown as far north and inland as Uvalde and Houston.
Originally three different primary species of avocado were identified: Guatemalan, West Indian and Mexican.
The Mexican strain has better cold tolerance, a criteria for selection for our area. However, the Mexican varieties have poor salt tolerance. The West Indian strains have better tolerance for salinity but lack cold hardiness, being valued primarily as a rootstock for grafting on other strains.
Various cultivars have been developed through crosses of these strains.
Be aware that the low temperature tolerance shown for a cultivar applies to a mature (3- to 5-year-old) tree. Younger trees require frost and freeze protection, such as covering with blankets (not plastic or tarps) and even to the extent of supplemental heating. Note the planting technique mentioned below that will help protect a young tree.
Selecting planting site
There are three primary factors to be considered in selecting a planting site for the avocado: full sun, good drainage and wind protection. Allowance must also be made for the potential size of the tree.
The south side of a building will provide a certain amount of winter wind protection. The avocado performs better in a lighter, loamy soil and will not tolerate poor drainage.
Recommended planting technique
A suggested planting technique is to build a mound 3 to 4 feet in diameter and about 1 foot tall, forming a depression in the center of the mound and planting the tree with the graft at or below the surface of the mound.
Soil will be available to rake above the graft at onset of a severe cold spell. If the top freezes, the tree will re-sprout from above the graft coming back true to variety.
Nursery trees are grown in containers of soilless media, much of which should be washed off just before planting, allowing the roots intimate contact with the soil. The newly planted tree should be staked.
Protecting young trees
The green tissue on the trunk and limbs of the young trees are very susceptible to sunburn and must be protected for one or two years until the tree develops enough leaves to be self-shading.
Options include caging with a structure-supporting shade cloth in the summer (and doubling for freeze protection covers in winter) or painting the trunk and limbs periodically with a 50-50 mix of water and white latex paint.
Watering is similar to other fruit trees – slow, deep and not allowing water to stand more than two hours. Drip irrigation is preferred, if practical.
Ongoing care and fertilization
As with anything planted to survive in the environment, there is necessary ongoing care for the avocado tree:
- The soil should be tested and amended pre-plant and at two- or three-year intervals.
- Nitrogen should be applied in split applications. Refer to Texas AgriLife Extension Bulletin EHT-018 for details at aggie-horticulture.tamu.edu; click the “Fruit and Nut” tab.
- Eliminate weed and grass competition by mechanical or chemical means plus mulch.
- Prune only as required to maintain desired size and shape or remove damaged limbs.
Other than protection from sunburn and freezing/frosts, the avocado is not plagued with myriad problems and challenges.
Leaf tip and edge burning during hot, dry weather are caused by water stress and/or salinity. Water deep and often.
Few insect problems are reported, but opossums are known to enjoy the ripe fruit and will help harvest. Wherever grown, avocado is plagued by fungal pathogens infecting the leaves and fruit, and one in particular called anthracnose, caused by the fungus Colletotrichum gloeosporioides, is a more common disease but controllable with an approved spray program.
Fruit of your labor
Avocados are a staple product of Tex-Mex cuisine in Texas and are commonly served in restaurants around the country and some parts of the world. The fruit of the avocado has a unique flavor and serves as an exemplary complement to a variety of dishes.
In addition to the avocado’s unique flavor, the fruit also has nutritional benefits.
Avocados have more potassium than bananas and are a good source of vitamins K, E and B. The flesh is about 15 percent oil or fat, much of which is in the healthy, monounsaturated form. The fruit has been studied for its role in lowering cholesterol and limiting certain forms of oral cancer.
Avocado can claim spot
in home orchard
The avocado tree is relatively easy to manage, short of the need for sun and cold protection. Overall care is similar to citrus, making the avocado a contender for a spot in the home orchard.