The avocado tree, a medium to large evergreen tree, produces a fatty, delicious fruit and dark green, shiny leaves. It grows well outdoors in temperate areas such as California, Texas and Florida. It is popularly used in Mexican dishes, dips and in sandwiches. Grafting branches from one avocado tree to another to propagate the tree.
Avocados do not produce true trees from seed, meaning that the avocado seed inside of most fruit you get from the store will not produce the same avocado, or an avocado tree at all. Seedlings from avocado trees will not often produce edible fruit for 10 to 15 years. Trees grown from a seed are best used as rootstock for grafting purposes. Rootstock provides the roots and trunk for the full-grown avocado tree.
To graft avocado you need a strong rootstock as well as a scion. A scion is a single bud or stem from a tree that produces desirable fruit. The best rootstock is resistant to diseases and adapted to the soil in the area it is planted. The scion is collected from 1-year-old wood.
A scion is collected from a tree with desirable fruit and cut at the bottom so the inner green layer of the branch is exposed. This is called the cambium. The scion cambium must come in contact with the exposed flesh of the rootstock. Once the flesh comes in contact, it is secured using grafting tape or grafting wax. The graft will take within 10 to 15 days.
Grafting is done in the spring or fall when the avocado bark separates easily from the wood of the tree. The weather should be warm enough so that the union will take, but not so late so that hot weather damages the union.
Whip grafting uses a scion cut so that it is wedged. Another wedge is cut into the rootstock and the two are taped together.
Bark grafting uses a scion cut into a wedge, which is then slid under the bark of the understock.
Budding is the use of a single bud cut off of the avocado branch so that a small shield of cambium is exposed behind it. The rootstock is cut so that a T-shaped area of the cambium is exposed. The bud is slid into this T-cut and waxed to hold it in place.