GRAFTED AVOCADO TREES
Avocados have been described as one of the most nutritious fruit in the world. They contain a well balanced supply of protein, carbohydrate minerals and vitamins. The pulp of the fruit is yellowish to green in color and the skin color varies from yellowish green to dark green to dark purple depending on the variety. The pulp of the avocado varies from a watery consistency through to a buttery consistency with favoured commercial varieties having a high oil content and nutty flavour. The seed size in grafted avocado trees is around 30% of the the whole fruit.
The scientific name of avocado is Persea americana belonging to the Family Lauraceae. This is the same Family that Camphor Laurels belong to. When leaves of avocados are crushed they exude an aniseed odour and this odour is particularly obvious in Fuerte avocados which helps in the identification of this variety. Leaves are large , glossy and dark green and the canopy of avocados is quite dense. The flowers occur as panicles at the end of branches and are small and lacking in petals.
Grafted avocado trees grow to be quite large trees reaching a height of 10 to 12 meters. The habit of avocado trees varies considerably depending on the variety. For example, the variety Reed tends to be upright in growth habit while Fuerte tends to be a large spreading tree.
The root system of avocados is characterized by a tap root with a number of well developed major roots which serve to anchor the tree in deep soils well. Avocados are not efficient at the uptake of water because they produce few root hairs and any root damage can have an immediate impact on the health of trees. Avocados are susceptible to Phytophthora cinnamomi which attacks the roots can affect trees growing in poorly drained soils.
Requirements for Healthy avocado plants
Avocados require deep well drained soils to grow well and not suffer from root rot. It is not worth planting avocados in shallow soils which a stoney or clay subsoil which is poorly drained because eventually they will suffer from Phytophthora root rot. Ideally soils should be at least 1.5 meters in depth. Freely draining soils like sandy soils or deep red soils are often infertile and require the addition of nutrients to improve fertility. A pH of 5.5 to 6 is ideal for avocados.
Detailed information about growing avocados can be found here.
Pests and Diseases of Avocados
The biggest problem growing avocados is the disease “Phytopthora” which is a fungus that grows in the soil that attacks the feeder roots.
Avocado fruit matures in the winter months with the Hass variety in northern NSW having a high oil content from June onwards.
“Hass”: Hass is the main commercial variety of avocado. It is a large tree with high quality fruit and is of the Guatemalan race. This variety originated in California from a seedling grown in 1926 by Rudolf Hass who named the avocado after himself.
The fruit are large weighing 200 to 300 grams and turn dark black when fully ripe. These avocados are creamy and have a nutty flavour and the flesh has a high fat content.
“Fuerte”:Fuerte avocados are a cross between the Mexican and Guatemalan types and are relatively cold tolerant. They produce green pear shaped fruit with thin skin. The fruit remains green when fully ripe.
Fuerte trees are vigorous and spreading and so have to be spaced widely apart in orchards.
“Wurtz”:Wurtz is described as a semi dwarf variety of avocado reaching about 4 meters in height. It is an attractive compact tree with weeping habit. It has pear shaped green fruit of high quality.
While you may read that there are 2 groups of avocados based on flowering behaviour – type A and Type B. Avocado trees are self pollinating and it is not necessary to plant other varieties in order to get good fruit set. For more information about pollination see here.
Details of Nursery Plants
Grafted Hass avocado trees are grown in 4L bags 80 cm to 1m in height supported by a 75cm bamboo cane. All avocados are grown on benches in order to prevent disease. They are irrigated with filtered water and initially grown in biodegradable tubes to minimise the presence of any plant pathogens. They are drenched regularly with Phosphonic acid which maintains root health.
Grafted trees will produce fruit within a year or two. Budwood for grafting is taken from mature trees, This budwood or “scion” has different hormone levels to the rootstock enabling flowering.
Avocado plants purchased online are $60 which includes GST and postage.
Hass and Fuerte avocados are available online now. We ship to NSW, Victoria and Brisbane area (postcodes 4000 – 4224) only.
We send trees with Australia Post in a strong cardboard box and post on Mondays to ensure that the plant reaches it’s destination before the weekend.
For wholesale orders of 30 plants or more please click here.