Planting conifers, the trees most often used for Christmas trees, requires careful timing. Maximizing survival and growth rate requires aligning the planting date with the species’ biological needs for establishing a robust root system. Since these trees take several years to reach a usable height, successful first-year establishment is the defining factor for the future health of the plantation.
The Optimal Planting Window
The universally recommended time for planting Christmas trees is early spring, after the ground has fully thawed but before the buds begin to swell and break dormancy. This period, often late March to early May depending on the geographic region, provides the ideal environmental conditions for root growth. The goal is to plant the tree while the above-ground parts are still dormant but the soil is warm enough to encourage development.
New roots begin to grow actively in soil temperatures above 40°F (4°C). Planting when the soil is cool and moist allows the tree to focus its energy on subterranean growth before the stress of high summer heat begins. This head start on root establishment helps the young conifer cope with dry periods later in the growing season.
Planting during this window ensures the developing root system has access to consistent soil moisture from spring rains. This maximizes the time available for the roots to anchor the tree and absorb water and nutrients before summer heat forces the tree into dormancy. Prioritizing root establishment in the cool, moist spring achieves significantly higher survival rates.
Secondary Planting Considerations
While early spring is the best time, planting can also be done in late fall after the tree has entered full dormancy, typically in late October or November. This alternative timing is less ideal and is only advisable in areas with mild winters or if the spring window was missed. Fall planting carries risks related to the onset of cold weather before the roots can settle into the new soil.
One major threat is frost heaving, which occurs when repeated cycles of freezing and thawing in the soil push small, shallow-rooted seedlings out of the ground. This process breaks the soil-to-root contact and leaves the root system exposed to air, leading to rapid desiccation and death. Fall-planted trees are also susceptible to winter desiccation, losing moisture through needles on windy days but unable to replace it because the ground is frozen solid.
Winter desiccation is problematic for evergreens, as they continue to transpire water even during colder months. If the ground freezes deeply, cutting off water absorption, the resulting moisture stress can cause the needles to turn brown, sometimes called “winter burn.” Fall planting requires proactive measures to mitigate these cold-weather risks.
Site and Seedling Preparation
Successful planting involves careful site and stock preparation. The site should provide full sun exposure and soil with good drainage, as conifers do not tolerate waterlogged conditions. A soil test should confirm the pH is within the optimal range for most conifers, typically between 6.1 and 7.3.
Preparation may involve tilling or deep plowing the site a year in advance to loosen compacted soil and improve moisture infiltration. Dense grass or weeds must be controlled prior to planting to eliminate early competition for water and light, a leading cause of seedling mortality. Proper site preparation can shave a year or two off the time it takes for the trees to reach maturity.
Seedling stock must be handled with meticulous care from the moment it is received until it is planted. Whether bare-root or containerized, the roots must be kept continuously moist, cool, and protected from exposure to sun and wind. For bare-root stock, any exposure to air for even a few minutes can drastically reduce survival rates. If planting cannot happen immediately, the roots should be stored in a cool, dark place or temporarily buried in a practice known as “heeling-in” to keep them dormant and hydrated.
Immediate Post-Planting Care
The first few weeks after planting require consistent, focused attention to encourage root establishment. Immediately following planting, the soil around the seedling must be thoroughly watered to settle the soil and eliminate air pockets. This initial watering establishes good soil-to-root contact.
Following the initial saturation, the watering regimen must maintain consistent moisture without causing saturation, often described as following a wet-dry cycle. During the first growing season, newly planted trees need regular watering because their limited root system cannot access deeper soil moisture. Watering should continue until the ground freezes in the fall to ensure the tree is well-hydrated going into winter.
Applying a layer of organic mulch, such as straw or wood chips, is an effective step immediately after planting. Mulch helps regulate soil temperature, retain moisture by reducing evaporation, and suppress competing weeds. For fall or highly exposed spring plantings, mulch also helps insulate the soil, reducing the risk of frost heaving and protecting the roots from cold damage.