Hass avocado

Sun

Full sun, sheltered from strong winds; protect newly planted trees from intense afternoon sun in very hot climates.

Water

Water deeply, then let the upper soil begin to dry before watering again. Keep the root zone evenly moist during flowering and fruit growth, but never waterlogged.

Soil

Deep, freely draining soil, preferably slightly acidic, around pH 6-7. Poor drainage, saline water and heavy, wet clay are major limitations.

Height

30-40 ft (9-12 m) unpruned; often maintained at 10-15 ft (3-4.5 m)

Spread

20-30 ft (6-9 m) unpruned

Flowers

Small, yellow-green flowers in branching clusters, usually in late winter and spring; timing varies with climate.

Foliage

Evergreen. Large, leathery, glossy green leaves; some older leaves fall as new growth develops.

Growth

Moderate to fast in warm conditions

Care needed

High

• Pollinators
• Heat tolerant
• Wildlife
• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Hard

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   7 ft (2 m)

2. After 1 year

   8 ft (2.5 m)

3. After 2 years

   10 ft (3.1 m)

4. After 3 years

   12 ft (3.6 m)

5. After 5 years

   15 ft (4.7 m)

About 16 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Fast

• Plant with the root flare at soil level; use a broad raised mound where drainage is marginal.
• Spread coarse organic mulch over the root zone, keeping it at least 6 in (15 cm) away from the trunk; avoid digging around the shallow roots.
• Water young trees regularly without keeping the soil saturated, and increase irrigation during hot, dry weather.
• Apply a citrus-and-avocado fertiliser according to its label during active growth; avoid heavy feeding and late-season nitrogen.
• Protect young trees from frost with horticultural fleece and shelter from wind; zone 9b is marginal for 'Hass', especially in frost pockets.
• Protect newly exposed trunks and branches from sunburn with a suitable white tree-trunk coating.

Pruning. Prune lightly after harvest and once frost risk has passed, removing dead wood, crossing branches and selected upright shoots to control height. Avoid severe pruning, which exposes bark to sunburn and reduces subsequent crops.

Grafted trees usually give their first worthwhile crop about 3-5 years after planting; harvest season varies widely by region, and fruit commonly takes about 12-18 months from flowering to maturity. Clip full-sized fruit with a short stalk attached and test a sample indoors: mature fruit should soften evenly within roughly one to two weeks, with the skin usually turning purple-black.

Late winter

Keep frost protection ready and check that winter rain is draining freely from the root zone.

Spring

Plant once frost risk has passed and the soil has warmed; begin light feeding as active growth starts.

Spring

Maintain even soil moisture during flowering and fruit set; avoid spraying insecticides around visiting pollinators.

Summer

Check irrigation frequently, renew mulch and protect young trunks from sunburn.

Summer

Where the local crop is mature, pick a sample and test its ability to soften before harvesting more.

Autumn

Reduce feeding as growth slows and prepare frost protection before cold nights arrive.

After harvest

In frost-free weather, prune lightly to keep the canopy accessible and remove damaged branches.

• Use as the main evergreen canopy tree in a warm-climate edible garden, allowing room for its mature spread.
• Plant in a sheltered home orchard with a compatible type B avocado, such as 'Fuerte', where space permits.
• Use as a leafy backdrop to lower edible planting, keeping a mulched, uncultivated area beneath the canopy.
• Train and prune for a manageable canopy beside a sunny courtyard, set well away from paving and buildings.

Garden styles it suits: Edible landscape, Backyard orchard, Food forest, Homestead, Mediterranean and Modern tropical.

Plant it with: Fuerte avocado, Nasturtium, Calendula and Sweet alyssum.

Wildlife: Flowers attract honeybees, native bees and other insects. The evergreen canopy provides shelter for birds, though avocados are not a suitable food to offer to pet birds or livestock.

• Phytophthora root rot: declining foliage and branch dieback often follow wet soil. Improve drainage, avoid overwatering and seek local advice on treatment; badly affected trees may need replacement.
• Frost damage: young shoots, flowers and fruit blacken after freezing weather. Choose a sheltered site, cover young trees and wait until new growth reveals the damage before pruning.
• Salt injury: brown leaf tips and margins can result from saline water or excessive fertiliser. Use low-salt irrigation water, reduce feeding and leach salts only where drainage is excellent.
• Avocado mites and lace bugs: mottled, bronzed or dropping leaves may indicate feeding damage. Identify the pest locally, conserve beneficial insects and use only locally approved treatments when necessary.

Leaves, bark, skin and seeds contain persin. Avocado material can cause illness in cats and dogs, and swallowed stones can cause choking or intestinal blockage; horses and birds are especially susceptible to serious, potentially fatal poisoning. Ripe flesh is edible for people, but the stone and skin should not be eaten; some people have avocado allergy.

• Fuerte avocado (Persea americana 'Fuerte')

  Its fruit is usually pear-shaped with a thinner, relatively smooth skin that stays green when ripe; 'Hass' usually has rougher skin that darkens on ripening.

• Reed avocado (Persea americana 'Reed')

  Produces large, rounded fruit with thick green skin that remains green when ripe, rather than the smaller, usually oval, dark-ripening fruit of 'Hass'.

'Hass' is named for Rudolph Hass, who selected and patented the original tree in California; 'avocado' comes through Spanish from the Nahuatl word ahuacatl.

Propagation. Buy a grafted tree to obtain true 'Hass' fruit and earlier cropping. Professional growers propagate it by grafting onto suitable rootstocks; seedlings do not come true and may take many years to fruit.

Accepted botanical name

Persea americana

In the US and Canada

Introduced in Hawaii, the lower 48 states, Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Belize, Costa Rica, Guatemala, Honduras, Mexico Central, Mexico Gulf, Mexico Southeast, Mexico Southwest and Nicaragua.

Measured

Average height 910 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.