Avocados are classified into three races: West Indian (W), Guatemalan (G), or Mexican (M).
• West Indian types - Fruit is large with glossy, smooth green skin. Low oil content. Ripens in Summer and Fall. Does well in humid, tropical climates. Cold-hardy to low 30's.
• Guatemalan types - Fruit is medium-sized with pebbly black skin. Ripens in Winter and Spring. High oil content. Cold hardy to high 20's.
• Mexican types - Fruit is small with thin skins that can be green or black. High oil content. Leaves have an anise-like scent and are used in cooking. Cold-hardy to low 20's.
Avocados are self-fertile. To increase fruit production, Type A avocados are planted with Type B avocados. Type A flowers open as female flowers in the morning, closing later in the day. The next day, the flowers reopen in the afternoon as male flowers. Whereas, Type B flowers open as female in the afternoon, closing later in the day. The next morning, the flowers reopen as male flowers.
A 5-gallon size grafted avocado may produce 2-3 fruit. A 15-gallon size grafted avocado will produce a 6-12 fruit.