The Sir Prize avocado, a “grandchild” of the widely recognized Hass avocado, emerged from a University of California breeding program. This variety, originating from an open-pollinated cross with a Hass seedling, offers distinct qualities and shares some characteristics with the Hass type, appealing to both growers and consumers.
Sir Prize Avocado Characteristics
The Sir Prize avocado fruit boasts a rich, nutty, and buttery flavor profile, with creamy, smooth flesh and a high oil content. These large, pear-shaped avocados typically weigh between 10 to 20 ounces. Their skin is dark green when immature, transitioning to a purplish-black color upon ripening. A distinguishing feature is its remarkably small, almond-sized seed, resulting in a high edible flesh-to-pit ratio of about 83%. The fruit is also less prone to oxidation after being cut or refrigerated, helping maintain its fresh appearance.
Growing Sir Prize Avocado Trees
Climate and Location
Sir Prize avocado trees thrive in warm, mild climates, ideally between 60 and 85 degrees Fahrenheit, and are best suited for USDA Hardiness Zones 9 through 11. Mature trees tolerate mild frost down to 26 degrees Fahrenheit, but young trees (under three years old) need protection below 32 degrees Fahrenheit. Planting sites should receive full sun, meaning at least eight hours of direct sunlight daily, to ensure optimal growth and fruit production. Protection from intense sun, especially above 90 degrees Fahrenheit, can be beneficial.
Soil and Planting
Sir Prize avocado trees thrive in well-draining soil, ideally a sandy loam, with a pH between 5 and 7. Alkaline soils (pH > 7) can hinder the uptake of essential nutrients like iron and zinc. When planting, avoid disturbing the roots and plant no deeper than the container level. For heavy clay soils, create a raised mound for improved drainage. Keep soil away from the trunk to prevent rot and fungal activity.
Watering and Fertilizing
Proper watering is crucial; Sir Prize avocado trees prefer less frequent but deep irrigation to encourage a robust root system. Newly planted trees need watering every other day for the first week, then two to three times weekly for a couple of months. Mature trees benefit from deep watering about once a week, adjusted for weather. Avoid overwatering, which can cause root rot.
Fertilization supports tree health and fruit production. Apply a balanced avocado or citrus-specific fertilizer, often slow-release, in spring after flowering. Organic options like composted manure, blood meal, or fish emulsion also provide nutrients.
Avocado trees require more nitrogen than phosphorus and potassium, so a higher N-P-K ratio is preferred. Avoid excessive nitrogen, which can attract pests like thrips. Soil and leaf tests can help determine specific nutrient needs.
Pollination Needs
Sir Prize avocado flowers are Type B: female parts are receptive in the afternoon, and male parts release pollen the next morning. While partially self-pollinating, planting a complementary Type A variety like Hass or Lamb Hass significantly enhances fruit set and yield. Type A flowers have female receptivity in the morning and male pollen release in the afternoon, creating an overlap with Type B. Bees are the primary pollinators, and adequate bee activity contributes to successful cross-pollination.
Pruning and Maintenance
Pruning Sir Prize avocado trees maintains shape, improves air circulation, and aids disease prevention. It also helps manage tree height for easier harvesting. For young trees, frequent pinching of terminal buds establishes desired form. The optimal time for pruning is typically after harvest, allowing new wood for the next fruiting season. Remove downward-facing or crisscrossing branches to promote better airflow.
Always use sharp, clean pruning tools to ensure clean cuts and prevent pathogen spread. Apply a 3 to 4-inch layer of mulch under the canopy to conserve soil moisture and suppress weeds. Keep it at least six inches away from the trunk to prevent collar rot.
Harvesting and Ripening Sir Prize Avocados
Sir Prize avocados mature earlier than some varieties, with harvest periods from October to January or January to April. Unlike many fruits, avocados do not ripen on the tree; they must be picked to soften. A key maturity indicator is when the skin turns from green to purplish-black while still on the tree; size is not reliable.
To test maturity, pick one of the largest fruits showing this color change. Allow it to ripen at room temperature, out of direct sunlight, which typically takes one to two weeks. If it softens properly, the remaining mature fruit can be harvested.
Ripening can be accelerated by placing the avocado in a paper bag with ethylene-producing fruits like apples or bananas. Refrigeration slows the process. Sir Prize avocados also have a reduced tendency to oxidize and brown quickly once cut.
Common Challenges
Sir Prize avocado trees can face several common challenges, including pests and diseases. Avocado thrips and persea mites are common insect pests that can affect foliage and fruit. Root rot, caused by the fungus Phytophthora cinnamomi, is a significant disease concern, often exacerbated by poor soil drainage and overwatering. Symptoms include wilting and leaf discoloration, with severe cases leading to tree decline. Anthracnose is another fungal disease that can affect avocado fruit, often appearing as dark spots on the skin.
Physiological issues include leaf drop, a normal occurrence where fallen leaves serve as beneficial mulch. Trees can also experience nutrient deficiencies, particularly iron and zinc, especially when planted in alkaline soils. Young trees are susceptible to frost damage, requiring protection in colder temperatures. Ensuring good drainage and applying mulch correctly are important preventative measures against root rot and other moisture-related problems.