The Wurtz avocado tree, often nicknamed the “Little Cado,” is a popular choice for home gardeners due to its compact, dwarf growth habit. This variety allows for harvesting homegrown avocados even in small spaces, making it a desirable selection for patio gardening or urban landscapes. Its manageable size simplifies maintenance and harvesting compared to full-sized counterparts.
Defining the Wurtz Variety
The Wurtz variety is recognized as the only true dwarf avocado tree in cultivation, making it suitable for container growing and smaller yards. At maturity, the tree typically reaches a height of 8 to 10 feet, though it may reach 10 to 15 feet if left unpruned. It naturally develops a dense canopy and an attractive weeping growth habit, which contributes to its ornamental appeal.
Structurally, the Wurtz is a hybrid of Mexican and Guatemalan avocado varieties. Avocado flower types are classified as A or B based on the timing of their male and female phases. The Wurtz is specifically an A-type flower. Although classified as A-type, the Wurtz is considered one of the most reliable self-pollinators among avocados, often producing a consistent crop without a companion tree.
Ideal Planting Conditions
Establishing a Wurtz avocado tree successfully depends on selecting the correct environment, as the tree requires specific conditions to thrive. This variety is best suited for mild climates, specifically USDA hardiness zones 9 through 11, and requires protection from freezing temperatures. Although it can tolerate mild frost conditions down to about 32°F, young trees are particularly susceptible to cold damage and may need to be moved indoors or covered during extreme weather events.
Avocado trees demand full sun exposure, requiring at least six to eight hours of direct sunlight daily for robust growth and fruit production. The most important soil requirement is exceptional drainage, as the tree’s shallow, fibrous root system is highly prone to waterlogging and subsequent root rot. If planting in the ground, heavy clay soils should be avoided. It is often beneficial to plant the tree on a raised mound to ensure water drains away quickly.
For container growing, which is an ideal method for this dwarf variety, the pot must have multiple drainage holes and be large enough to accommodate growth. When preparing the planting hole, it should be dug twice as wide as the root ball but no deeper, allowing the roots to spread easily. The tree should be positioned so the top of the root ball is level with the surrounding soil, and the excavated earth can be enriched with organic matter, like compost, before backfilling.
Essential Maintenance Practices
Once the tree is established, consistent maintenance is necessary to promote health and maximize fruit yield. Watering practices must balance the tree’s need for moisture with its intolerance for standing water, meaning deep and thorough irrigation is required when the top few inches of soil become dry. Seasonal adjustments are necessary, with more frequent watering during the warmer growing season, typically from February to September.
Fertilization should focus on providing high nitrogen, which is important for avocado shoot growth. Young trees benefit from light, frequent applications of a balanced fruit tree fertilizer every six to eight weeks during the growing season. For container-grown Wurtz trees, use a formulation specifically designed for potted fruit trees and apply it multiple times between late winter and early fall. Applying a layer of coarse mulch around the root zone helps maintain consistent soil moisture and temperature, but the mulch must be kept away from the trunk to prevent rot.
Pruning is important for the Wurtz to maintain its compact size and weeping habit, particularly for those grown in containers. Light pruning should be performed in late fall or early spring to shape the tree and remove dead or crossing branches. Frequent pinching of new growth on young trees encourages a denser, more structured canopy. Home gardeners should monitor for common avocado pests like the avocado lace bug and diseases such as root rot, which is a risk in poorly draining or overwatered soil.
Harvesting and Fruit Characteristics
The Wurtz avocado fruit typically ripens over an extended season, generally from late spring through early fall, or sometimes as late as December depending on the climate. Like all avocados, the fruit does not ripen while still attached to the tree, so determining maturity requires a test harvest. Growers should pick a single fruit when it appears mature and allow it to ripen indoors at room temperature for three to eight days.
If the test fruit ripens evenly and has a pleasant flavor, the rest of the crop is ready for harvest. If it shrivels or tastes rancid, wait a few more weeks before attempting another test. The fruit itself is medium-sized, generally weighing between 6 and 14 ounces, and has a characteristic pear shape. The skin is dark green, thin, and can be slightly pebbly, enclosing a creamy, light yellow flesh with a rich, nutty flavor and high oil content.