Relatives: laurels, camphor, cinnamon

Avocado trees are native to southern Mexico, though were being cultivated from the Rio Grande down to central Peru before the arrival of Europeans. Once 'discovered', this strange fruit was carried to moant parts of the tropical, subtropical and warm-temperate regions of the world. They naturally grow into quite large trees, with handsome foliage, and have fruits with strangely textured, thick. oily flesh that does not taste like anything else, but is now widely popular and appreciated by many nations worldwide. There are three main types of avocados -- Mexican, Guatemalan, and West Indian, with each varying in fruit and leaf type.


Avocado trees are attractive and give an exotic effect. Their form is often erect, and they often grow to ~ 29 feet (9 meters), though they can reach 60 feet (18 meters), with a trunk 30-60 cm in diameter. Avocados can grow for much of the year in warm areas, though tend to just have 1-2 flushes of growth in cooler regions. The bark is dark grey-brown and, if injured, secretes a white substance.

LEAVES: Mostly evergreen, though leaves may be shed during drought periods or in cold winters. Attractive, alternate, dark glossy green above, paler green beneath. Young leaves often have a reddish-bronze tinge. Are usually long and oval, with pointed tips, though can be more elliptic, varying in size. Leaves of West Indian cultivars are scentless, those of Guatemalan cultivars sometimes have an anise-like scent, whereas those of Mexican cultivars have a strong anise aroma when crushed.

FLOWERS: Small, yellowy-green, fragrant, with six petal-like lobes, nine stamens and a central, single-celled ovary. They are borne in early spring before the first seasonal growth, though a few can occur at other times.

FRUITS: Avocados are classified as a single-seeded berry with the inner seed consisting of an oily endosperm layer around a central ovule. The fruits are pear-shaped, oval or almost round, depending on the cultivar. The skin varies in color, but is usually dark green, and may be thin or thick and pebbled, depending on cultivar. Beneath the skin is a layer of oily, rich, pale green-cream-colored flesh. It is a deeper green near the skin , becoming more yellowish nearer the single large, hard, inedible, ovoid seed.


Grows best in full sun, though can tolerate a little shade. Susceptible (likely to be harmed) to wind damage, which breaks branches and reduces fruit-set. It can also scar fruits, which leads to disease, bruising, etc. They can tolerate some salt, but need a sheltered spot in maritime locations as spray can burn the leaves. Some reports say they are very susceptible to too much chlorine. Once established, however, the avocado is a fairly tough tree.

TEMPERATURE: Avocados are warmer climate trees. West Indian trees can be seriously damaged at ~29 degrees Fahrenheit; Guatemalan trees are a little hardier, surviving short drops to 26 degrees Fahrenheit, with Mexican trees being the hardiest and surviving 21 degrees Fahrenheit. Established trees are much more cold hardy than young trees, which need extra protection. Frosts can damage early flowers, but trees sometimes re-flower later in the season, especially Mexican types. We recommend winter protection for both the avocado cultivars we carry, whether that be in a conditioned space or brought indoors as a winter house guest. If you plant or set your pot planted avocado outside, consider the following:

Cold and heat protection: Avocados need protection from both frosts and the sun for the first couple of years. When a severe freeze is being forecast, mound additional soil around the trunk for extra protection, then water thoroughly two or three days before the cold weather is expected. Young trees can be draped (not wrapped) with a blanket or quilt (never use plastic) during the freeze event. The corners of the covering should be pulled outward and anchored to the ground. Any additional practical heat source under the tented tree will probably save even the leaves. Examples include incandescent lights or other decorative lights....anything to generate a bit of heat which is trapped by the blanket or quilt.  (In the even of rain and cold, we tent the plant with a blanket and cover it with plastic to keep it dry.  Once the avocados have a couple of years growth, they will not need this protection for temperatures above 20 degrees F.
Protection from the sun: Avocados have almost no brown, woody bark like other plants. Notice that the stems and main branches of your tree are bright green. These branches and stems are photosynthesizing and providing food and energy for your tree, just like the leaves. However, this green tissue on the stems and bark is very susceptible to sunburn. Young trees do not have enough leaves to shade this bark and some special care should be given during this first year or two.

POLLINATION: Avocados are considered either Type A or Type B, which refers to the timing in which the male and female flowers bloom. A mature avocado tree will produce thousands of flowers during the bloom period, each of which contains both male and female organs. HOWEVER, these organs are not active at the same time, but rather have distinct male or female phases. Each flower will open for two days, beginning with active female organs on the first day, then closing in the evening and re-opening on the second day with active male organs. Type A avocados open as female flowers during the morning of the first day, and open as males during the afternoon of the second day. Type B avocados have female flowers during the afternoon of the first day, and male flowers during the morning of the second day. Because these flowers are not all opening at the same time or on the same day, there will be an operlap of male and female flowers blooming on a single tree. This means that Avocado trees are considered self-fertile, but there is a better chance of pollination and improved fruit set if a Type A cultivar and a Type B cultivar are planted together.


There are three main types:

Mexican: smaller fruits, large seeds. Fruits mature from summer-early autumn. There are very few 'pure' Mexican cultivars because of poorer fruit quality, and they are usually hybrids with other types. Flesh has high oil content.

Guatemalan: Skin is usually hard, thick and is often gritty, has a small seed. Fruits mostly ripen from late autumn-spring, depending on the cultivar. The may be known as 'winter' or 'hard-shell' avocados.

West Indies: skin is thin, smooth, leathery, pliable, has a large seed that is often lose within the center. Fruit mature from summer-early autumn.