The olive tree (Olea europaea) is an ancient, long-lived evergreen species native to the Mediterranean region, prized globally for its fruit and oil. This resilient tree has been cultivated for thousands of years, adapting to a variety of arid and semi-arid conditions. Its final height is highly variable, influenced by both its inherent biology and the management practices of its growers. Understanding the factors that determine this size is important for anyone planning to cultivate this plant.
Standard Mature Height and Spread
The typical height of an olive tree depends on its environment and commercial management. A mature, cultivated olive tree usually reaches 15 to 30 feet, a range preferred by most growers for ease of harvesting. The canopy spread is often equal to or greater than its height, resulting in a characteristic wide, rounded appearance. Olive trees have a moderate to slow growth rate, taking decades to fully establish their mature form.
An olive tree is considered mature when it enters its prime fruiting stage, though it continues to increase in size afterward. Unpruned or ancient specimens demonstrate the species’ true genetic potential, often reaching heights of up to 40 or 50 feet. These larger trees are typically found in older groves where human intervention has been minimal. Regular pruning is the main reason most olive trees in orchards remain significantly shorter than this maximum potential.
Natural and Genetic Factors Affecting Final Size
The ultimate size an olive tree achieves is determined by its genetics, specifically the cultivar selected. Certain varieties, such as ‘Arbequina’ and ‘Arbosana’, are naturally smaller and exhibit low vigor, making them ideal for high-density plantings. In contrast, varieties like ‘Manzanilla’ and ‘Picual’ possess medium to high vigor, predisposing them to grow into larger trees if left unmanaged.
The local environment acts as a limiting factor on this potential, with soil quality and climate playing significant roles. Olive trees thrive in well-draining soil; growing in poor ground or shallow substrates will naturally stunt the tree’s growth and reduce its eventual height. Prolonged environmental stress, such as severe drought or exposure to low temperatures, can slow the already gradual growth rate. Since growth is slow, often only 1 to 2 feet per year, environmental limitations have a cumulative effect over many years.
Cultivation Practices for Height Management
Cultivation practices are instrumental in controlling the functional height of an olive tree, especially in commercial orchards. The primary method is pruning, used to maintain a manageable height, typically under 20 feet, to facilitate harvesting by hand or machine. Pruning also opens the canopy to sunlight and air circulation, promoting better fruit production. Growers often employ specific shapes, such as the open vase, which involves removing the central leader to limit upward growth and encourage lateral spread.
Height management begins early through training, which establishes the basic structure. This often involves ensuring a clean, straight trunk for the first 3 to 4 feet to allow mechanical harvesting equipment to grip the trunk. For young trees, excessive pruning is avoided initially to maximize leaf surface area for healthy development. In modern high-density systems, cultivars like ‘Arbequina’ are chosen because their naturally small stature allows them to be kept at a maximum height of about 9 to 10 feet with annual renewal pruning.