Black Berry plant

Overview of the Hass Avocado Tree

The Hass Avocado Tree is the most commercially popular avocado tree in the world. It was first grown by Southern California horticulturist Rudolph Hass, who named the variety. The fruit is known for its excellent taste, good size, long shelf life, and high yields. In fact, 95% of the California avocado crop comes from the Hass variety.

Fruit Description

Hass Avocados have dark green, bumpy skin that turns a purplish-black color when ripe. They are prized for their:

• Taste: Rich and creamy.
• Size: Medium to large.
• Shelf Life: Excellent, making them ideal for both commercial and home use.

The fruit matures on the tree and ripens after picking.

Climate and Sun Requirements

Heat Sensitivity

In areas like the San Fernando Valley, young Hass avocado tree leaves are susceptible to sun damage in the hot, dry summers. The large surface area of the leaves makes them prone to yellowing and browning. To prevent this, plant the tree where it will receive morning sun and afternoon shade.

Cold Sensitivity

Near freezing temperatures during winter nights can damage the Hass Avocado tree, causing leaves to blacken and dry. The tree performs best in coastal areas like Malibu, Ventura, Santa Barbara, and San Diego, where the ocean regulates temperatures. Protect the tree from cold winds in winter, especially in microclimates found in areas like Glendale, Burbank, Pasadena, and Sherman Oaks.

Botanical Information

The Hass Avocado Tree is a medium to large tropical evergreen with:

• Foliage: Large green to dark green leaves.
• Flowers: White flowers grouped in inflorescences. The flowers open as both male and female at different times, allowing for self-pollination depending on temperature.

To ensure cross-pollination, many growers plant Type A (Hass) alongside Type B (Fuerte) avocados. Avocado trees can be alternate bearing, producing a large crop one year and a smaller one the next.

Planting and Watering

Location

• Wind Protection: If planting in a windy area, place the tree near a windbreak.
• Sun Protection: In hot climates, plant where the tree receives morning sun and afternoon shade to avoid fruit sunburn.

Soil and Watering

• Soil: Plant in well-drained soils with moderate temperatures.
• Watering: Newly planted trees should be watered twice a week to establish strong roots.

Maintenance and Care

Pruning

Prune the tree in winter to maintain shape and size. Ensure the lower branches (the skirt) do not touch the ground.

Irrigation and Mulching

• Keep the soil moist, but ensure the trunk remains dry to prevent rot.
• Mulch the root area with natural leaf litter or organic chunky mulch for best results.

Fertilization

Fertilize with nitrogen throughout the year in small doses. Regular fertilization supports healthy growth and fruit production.

History of the Hass Avocado

The Hass Avocado has an interesting history, originating in La Habra Heights, California. In 1926, Rudolph Hass, a postman and amateur horticulturist, purchased a seedling that turned out to be an exceptional variety. Initially, Hass planned to graft Fuerte avocados onto this rootstock, but when the grafts failed, he decided to grow the tree from the seedling. The result was the Hass avocado, which eventually became the dominant variety in the global avocado industry. By the 1970s, Hass avocados made up the majority of avocados sold in the U.S. Today, the Hass avocado is the leading variety grown worldwide, thanks to its excellent flavor, year-round growing season, and hardy nature.