The olive tree, Olea europaea, is a hardy, long-lived species native to the Mediterranean basin. Successfully establishing this evergreen tree depends heavily on selecting the correct planting time. Planting outside the optimal window can severely hinder the establishment of a robust root system. Improper timing exposes the young tree to temperature extremes, potentially resulting in root shock, stunted growth, or death. Correct timing ensures the tree focuses its energy on root development before facing the stress of summer heat or winter cold.
Optimal Seasons for Planting
The two most advantageous windows for planting olive trees are early spring and early fall, as both periods offer moderate conditions conducive to root establishment.
Planting in early spring, typically between April and May, is preferred in regions with colder winters. This timing allows the newly planted tree the entire growing season to develop its root system before the arrival of deep frosts. Spring planting provides a necessary head start for the tree to build resilience against cold temperatures.
Planting in early fall, often around September, is highly effective in areas with mild winters. During this period, air temperature moderates, but the soil retains residual warmth from the summer months. This encourages strong root growth throughout the cooler fall and winter, preparing the tree for a vigorous growth spurt the following spring. Fall planting should only be considered where winter temperatures rarely drop below 30°F (-1.1°C), as new transplants are vulnerable to freeze damage.
Climate and Temperature Requirements
The decision to plant must align with specific temperature thresholds to ensure the young tree’s survival. Olive trees should not be planted when the ambient air temperature consistently exceeds 90°F, which causes severe heat stress on the foliage and rootball. Conversely, planting when temperatures are consistently below 50°F severely hinders root growth.
Newly transplanted olives are extremely vulnerable to freezing, so planting must occur well after the last expected hard frost in spring or well before the first expected hard frost in fall. Exposure to temperatures dropping below 30°F (-1.1°C) can cause significant damage to the vulnerable tissues of a young tree. The tree’s natural dormancy period, which occurs during the cooler months, is the ideal time for planting because the tree’s energy is directed toward root growth rather than producing new foliage. This focus on subterranean development helps prevent transplant shock.
Timing Based on Tree Type
The form in which the olive tree is purchased significantly influences planting flexibility.
Container-grown olive trees are the most common stock and offer the greatest leeway in scheduling. These trees can technically be planted year-round, provided the soil is not frozen and temperatures are not extreme. However, container-grown trees benefit immensely from being planted during the optimal spring or fall windows.
Bare-root olive trees are less common, but their planting time is non-negotiable. Bare-root stock must be planted when the tree is in its deepest state of dormancy, typically during late winter or very early spring. This narrow window occurs before the buds begin to swell and before the tree allocates energy to above-ground growth. Planting a bare-root tree outside of this dormant period will almost certainly lead to transplant failure.