Planting evergreen trees, which include both needle-bearing conifers and broadleaf varieties, is highly dependent on timing for success. Because these trees retain their foliage year-round, they continue to lose moisture even when the ground is cold. The goal of proper planting is to minimize transplant shock and maximize the period during which the tree can establish a healthy root system before environmental stress occurs. Selecting the correct planting window is the most important factor determining whether a new evergreen will thrive.
The Optimal Planting Seasons
The two most favorable windows for planting evergreens align with the moderate temperatures of the calendar year. These periods provide the best conditions for root establishment without the stress of intense heat or severe cold. Early spring is the first ideal time, specifically after the ground thaws but before the tree’s buds begin to break. This window capitalizes on high soil moisture from winter melt and cooler air temperatures, which minimize water loss from the foliage.
The second optimal period occurs in early to mid-fall, typically about six weeks before the first hard freeze is expected. During this time, the air temperature cools faster than the soil temperature, directing the plant’s energy toward root development. A strong root system can be established while the above-ground growth remains dormant, preparing the tree for winter.
Timing Adjustments Based on Tree Type
The preparation method used by the nursery significantly influences how flexible the planting schedule can be. Trees sold as balled and burlapped (B\&B) suffer some root severance during harvest, despite having a large mass of soil wrapped around their roots. Because of this disturbance, B\&B evergreens should be restricted to the true dormancy periods of early spring or late fall to minimize shock.
Containerized stock offers the greatest flexibility because the root system remains completely intact within the pot. These evergreens can often be planted later into the spring or earlier into the fall, as they experience less transplant shock. The primary requirement for planting container stock outside the peak windows is maintaining consistent watering.
Bare root evergreens, which have all the soil washed away from their roots, are the most sensitive type. They must be planted strictly in the very early spring, immediately after the ground thaws, while the tree is fully dormant to prevent the roots from drying out.
Avoiding High-Risk Planting Windows
Certain times of the year present significant risks that can severely inhibit a newly planted evergreen’s survival. Mid-summer is a high-risk period that should be avoided due to heat stress and rapid moisture loss. High temperatures cause the foliage to transpire excessively, meaning the tree loses water faster than its newly disturbed roots can take it up. This imbalance often leads to severe transplant shock and failure to establish.
Planting during deep winter is also discouraged, even if the ground is temporarily unfrozen. The primary danger is desiccation, commonly known as winter burn. When the soil is frozen, the roots cannot absorb water to replace moisture lost by the foliage. This deficit, combined with harsh winds and bright winter sun, starves the tree of water, leading to browning of the needles and potential death.
Regional Climate Considerations
The general advice of planting in spring and fall must be adjusted according to the specific USDA Plant Hardiness Zone of the location. Gardeners in northern climates, which correspond to colder zones, face a shorter planting window in both seasons. In these colder regions, the early spring window is particularly important because the fall window closes rapidly when freezing temperatures arrive.
Planting too late in the fall prevents the roots from establishing sufficiently before the ground freezes solid. Conversely, in southern climates, which feature warmer zones, the traditional winter months often become a viable third planting season. Since the ground rarely freezes in these areas, root growth can continue throughout the late fall, winter, and early spring, offering an extended opportunity for successful establishment.