Background Info
Avocados are a delicious, nutritious fruit that are native to Central and South America, Mexico and the Caribbean. The tree that bears the fruit is a tropical evergreen tree of the genus Persea. It has been cultivated in these areas for centuries and is now grown in many other hot, regions worldwide. Starting an avocado tree from a seed is an inexpensive and rewarding DIY project, that starts with a process called “grafting.”
The Grafting Process
Grafting is a horticultural technique in which parts of plants are joined together in order to create a combination that is stronger and more productive than either of the parts alone. In the case of growing an avocado tree, the scion (or top) of an avocado tree is joined to the rootstock (or base) of another. This process stimulates the tree to produce fruit.
Choosing Quality Materials
To ensure success when grafting an avocado tree, it is essential to start with healthy trees or parts of trees. Good scions should be twelve to eighteen inches long, with a diameter of one fourth of an inch or smaller. The branch should have at least three to four sturdy shoots and a visible bark thickness that goes around the wood. Rootstock should be healthy, disease-free plants with strong roots. Keep in mind that a seed-grown rootstock may take three to four years before it begins to bear fruit.
Preparing the Scion and Rootstock
Before grafting, the scion should be cut about one inch below a leaf node, where there is a bud or shoot. It is then cut into a wedge shape. The rootstock should be cut about one-half inch below a bud, slightly slanted, and this is the spot at which the scion will be grafted.
Grafting the Scion to the Rootstock
There are two types of grafting techniques: cleft grafting and whip grafting. Cleft grafting is when the scion and rootstock are cut into a V-shape. The scion is wedged into the rootstock and then held in place with binding material. Whip grafting involves cutting a small groove in the rootstock, using it as a channel to slip the scion into. This method is best suited for younger rootstocks, as they are easier to carve into.
After the Graft
After the graft is complete, the tree should be monitored for signs of growth. If the graft was successful, the union will be swollen and the shoots will begin to grow soon afterwards. During this time, it is important to ensure that the rootstock does not become too wet or too dry. It should be kept slightly moist, not wet.
Researching Grafting youtube
Since grafting an avocado tree is a complex process, it is recommended to research the topic thoroughly before attempting it. After gaining a basic understanding of the steps, it would be wise to watch a few videos about the process on youtube for advice, instruction and visual references. Once grafted correctly, the tree should produce within two to three years.
Graft Compatibility
When selecting the scion and rootstock, it is important to ensure graft compatibility. Although varieties of avocados will all have similar structures, they may have different growing requirements and physical characteristics. For best results, pick scions and rootstocks of the same avocado variety and season.
Growing Environment
Avocados can grow in a wide range of climates, but the optimum temperature range for successful growth is between 15°C and 25°C. If temperatures drop below this range, growth will be severely stunted and the tree may not survive. During the summer, it is advised to provide shade or move the tree indoors, especially in hotter climates.
Fertilization Patterns
Although seed-grown avocados will not require regular fertilization, avocado trees grafted from another tree will need regular fertilizer applications. Start applying a balanced fertilizer with a high nitrogen content to the soil in late spring. Increase the frequency of applications if the leaves start to yellow.
Pruning and Watering
Avocado trees should be watered regularly and deeply, especially during the summer months. Avoid over-watering and water logs, as these can cause root rot. Pruning should also be done in late winter or early spring. Prune back any dead wood or branches that are not producing fruit.
Harvesting and Preservation
Avocados picked directly from the tree are the tastiest and most nutritious. When harvesting the fruit, make sure to wait until the avocados have fully ripened, as they will not ripen further after they have been removed from the tree. To preserve your avocados longer, they can be stored in the refrigerator or freezer.
