Avocado Tree Hass - Persea americana

The Persea americana 'Hass' is a highly regarded variety of Avocado trees, known for the excellence of its fruits, which are also the best-selling in the world. These are the famous 'Hass' avocados with a lumpy skin, turning purplish-brown when ripe. Their flesh is non-fibrous, creamy in texture, with a slightly nutty flavour. The 'Hass' avocado tree can be grown on open ground in the mildest regions, such as the orange zone, as its hardiness is limited to -4°C. Elsewhere, it is cultivated in pots, ideally in a greenhouse or conservatory, or on a well-exposed balcony, sheltered from the wind, before being overwintered frost-free in a very bright room. It is possible to obtain fruits between 4 and 8 years after planting with a good combination of heat and humidity.

The Persea americana is an evergreen tree belonging to the laurel family. It is native to Central America and found in humid forests, from almost sea level up to 2000 m. Depending on its origin, Persea americana is divided into three geographical types, more or less hardy: the Mexican avocado tree (subtropical), the Guatemalan avocado tree (subtropical), and the West Indian avocado tree (tropical). It is intensively cultivated in many subtropical regions and even in the south of Spain, where it is grown for its fruits, avocados, which are rich in lipids, vitamins, and minerals. The avocado tree is a medium-sized tree that can reach twenty metres in height but more often measures about ten metres in its natural environment. Its crown is ample and bushy, its trunk is covered with a grayish and fissured bark. The leaves are alternate, elliptical, entire, with smooth edges, acuminate, measuring 20 to 30 cm by 10 to 15 cm, the base is pointed, the ventral surface is dark green, shiny, the veins are light green, the dorsal surface is dull, glaucous light to white. They fall every year, but after the tree has already formed its new annual foliage, it remains evergreen. Its flowers are successive hermaphrodites and measure from 5 to 10 mm. There are two different types of avocado inflorescences: determinate and indeterminate. In a determinate inflorescence, the end of the shoot that bears the flowers will end in a flower. Indeterminate inflorescences end in a vegetative bud. The avocado fruit is pear-shaped (pyriform), oval or round, 7 to 20 cm long, weighing 100 to 1,000 g. From a botanical point of view, the avocado is a berry with a single seed and not a drupe, as the endocarp is fleshy. It has a large oval central seed, 3 to 5 cm long.

The Persea americana 'Hass' is a renowned variety whose fruits are standard on our stalls. It can reach 7 m in open ground in our latitudes but only 2 to 3 m in height when grown in pots. The fruit is initially green, with a granular skin, then black-brown with violet reflections when ripe. It is climacteric: it only ripens after picking. Harvesting and storing it in a cool and dry space is necessary for it to ripen. The large-sized fruits have firm, stringless flesh. They weigh an average of 300 grams and contain numerous vitamins, minerals, and trace elements. 'Hass' is a self-fertile protogynous cultivar, capable of self-pollination, as its flowers open twice, first as female and then as male. However, it is preferable to cultivate several plants nearby to ensure pollination. It is classified as category A, and it is recommended to plant category B varieties nearby for good pollination, such as 'Bacon', 'Fuerte', or 'Zutano'. Furthermore, fruits will only appear if the tree has sufficient sunlight and high humidity during the initial fruit formation phase.

The Persea americana 'Hass' can only be acclimated in open ground in our mildest winter regions, in warm oceanic or Mediterranean climates. It tolerates frosts of up to approximately -4°C. Elsewhere, it is cultivated in pots like a citrus tree, which allows it to be stored away from frost in winter in a bright but unheated room. A greenhouse can obtain the necessary humidity conditions for fruiting.