Persea americana: Avocado

Introduction

The large, lustrous dark green evergreen leaves and low-branching, open canopy of Avocado makes it a wonderful shade tree, but it is most often grown for the abundant production of its well-known, delicious, buttery fruits. Depending on cultivars and variety, the fruits may vary from smooth-skinned to rough, and yellow-green to purple. Commonly seen at 30 to 40 feet in height but capable of growing much larger, Avocado fits well into large residential landscapes in frost-protected locations. It can be pruned to an open spreading form or left to grow tall forming a rather narrow oval. Older trees become more rounded. The somewhat showy, greenish yellow flowers appear on terminal panicles in late winter to early spring and are followed by the large, pendulous, pear-shaped fruits, ripening late summer to early spring, depending upon variety.

General Information

Scientific name: Persea americana

Pronunciation: PER-see-uh uh-mair-ih-KAY-nuh

Common name(s): avocado

Family: Lauraceae

USDA hardiness zones: 9B through 11 (Figure 2)

Origin: native to Mexico and the tropical Americas

UF/IFAS Invasive Assessment Status: not assessed/incomplete assessment

Uses: shade; fruit; specimen

Description

Height: 30 to 40 feet

Spread: 25 to 35 feet

Crown uniformity: symmetrical

Crown shape: oval, round

Crown density: moderate

Growth rate: fast

Texture: coarse

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: entire

Leaf shape: elliptic to oval

Leaf venation: pinnate

Leaf type and persistence: evergreen, broadleaf evergreen

Leaf blade length: 4 to 11 inches

Leaf color: emerges shiny and reddish, becoming dark green on top and paler green underneath

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: pale green to greenish yellow

Flower characteristics: not showy; fragrant; emerges in clusters on terminal panicles

Flowering: late winter to early spring

Fruit

Fruit shape: pear-shaped

Fruit length: 3 to 8 inches

Fruit covering: fleshy; smooth to pebbly texture

Fruit color: yellow green to dark purple or almost black when ripe

Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem

Fruiting: ripens late summer to early spring

Trunk and Branches

Trunk/branches: branches droop; not showy; typically one trunk; no thorns

Bark: grayish brown and rough, becoming blocky with age

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: green

Current year twig thickness: medium

Wood specific gravity: unknown

Culture

Light requirement: full sun to partial shade

Soil tolerances: clay; sand; loam; alkaline; acidic; well-drained

Drought tolerance: moderate

Aerosol salt tolerance: moderate

Other

Roots: not a problem

Winter interest: no

Outstanding tree: no

Ozone sensitivity: tolerant

Verticillium wilt susceptibility: susceptible

Pest resistance: resistant to pests/diseases

Use and Management

Avocado trees grow quickly in either full sun or light shade on any well-drained soil. Trees should be watered regularly until established and later during droughts. A forest tree in its native habitat, Avocado respond well to a thick leaf mulch and periodic fertilization. Lawn grasses should be kept away from the trunk. The brittle wood of Avocado trees is subject to storm damage when trees grow taller than 50 feet in the open.

Some of the many cultivars available for variety of fruit production and season are: `Lula', `Tonnage', `Taylor', `Booth 7', `Booth 8', `Pollack', `Trapp', `Walden', `Linda', and `Itzamna'.

Propagation is by seed or grafting.

Pests

Mites and scale infestations can become quite serious in local areas.

Diseases

Root rots on poorly-drained soils and leaf-spotting diseases can be troublesome.

Redbay Ambrosia Beetle-Laurel Wilt Disease (RAB-LW) is a major threat to avocado trees and related species.

Reference

Koeser, A.K., Friedman, M.H., Hasing, G., Finley, H., Schelb, J. 2017. Trees: South Florida and the Keys. University of Florida Institute of Food and Agricultural Sciences.