Boxwood shrubs are popular evergreens prized for their fine-textured, dense foliage and structural versatility in the landscape. Their natural growth habit makes them excellent choices for formal hedges, topiaries, or foundation plantings, providing year-round color. Successfully establishing a boxwood requires attention to detail during planting, as proper installation is key to ensuring the shrub’s long-term health. Following a precise procedure for site selection, planting depth, and initial care will help this classic shrub thrive.
Preparation: Choosing the Site and Shrub
The longevity of a boxwood depends significantly on its placement, making site selection a primary step. Boxwoods prefer well-drained soil and will quickly decline in areas where water pools, as they are highly susceptible to Phytophthora root rot. The ideal soil should be neutral to slightly alkaline, with a pH range between 6.5 and 7.5, which facilitates optimal nutrient uptake. Performing a soil test before planting is wise to determine if amendments are needed to adjust the pH.
Most varieties perform best in partial shade, receiving protection from intense afternoon sun, especially in warmer climates. Direct sun exposure, particularly when combined with harsh winter winds, can cause the foliage to “bronze” or turn an undesirable reddish-brown color. A location sheltered from winter wind and scorching summer sun helps maintain a deep green color. When selecting a shrub, choose a specimen with uniformly dense, bright green foliage and firm branches, avoiding plants with yellowing leaves or visible pests or disease.
The Planting Procedure
When preparing the planting site, dig a hole two to three times the width of the root ball but no deeper than the root ball itself. This width encourages new roots to grow quickly into the surrounding, loosened native soil, promoting rapid establishment. Plant the boxwood slightly high, ensuring the top of the root ball sits one to two inches above the surrounding soil grade. This accounts for settling and prevents water from collecting around the trunk.
If the boxwood was container-grown, remove it from the pot and inspect the roots for circling growth. Circling growth is a common issue that can eventually strangle the plant. Use a sharp knife or hand pruners to make several shallow, vertical cuts down the sides of the root mass, encouraging the roots to grow outward. For balled-and-burlapped (B&B) shrubs, place the root ball directly into the hole, then remove all twine and wire wrapped around the trunk flare.
Once the shrub is positioned, remove the top one-third of the wire basket and burlap material to ensure the roots can grow uninhibited into the surrounding soil. Use the native soil removed from the hole to backfill around the root ball, tamping gently to eliminate large air pockets that could dry out the roots. Avoid adding organic amendments directly into the backfill soil. This can create a textural difference that prevents water from draining properly, leading to the “soup bowl” effect and subsequent root rot.
Post-Planting Care: Watering and Mulching
Immediate and thorough watering is necessary right after planting to settle the soil and fully eliminate any remaining air pockets. The goal is to saturate the entire root ball and the surrounding backfill area without creating standing water. This initial watering prevents transplant shock and ensures the roots make firm contact with the soil.
For the first week, water the newly planted boxwood daily to maintain consistent moisture while the roots begin to acclimate to their new environment. Over the next few weeks, gradually taper the watering frequency to two or three times per week. Always check the soil moisture before adding more water. Stick a finger a few inches into the soil near the root ball; if it feels dry, apply water, but if it is still moist, wait.
Applying a two- to three-inch layer of organic mulch around the plant helps retain soil moisture, regulates soil temperature, and suppresses weed competition. However, be deliberate with the mulch placement, creating a “donut” shape that keeps the material several inches away from the shrub’s central stem. Piling mulch directly against the trunk, often called a “volcano,” traps moisture and encourages the development of crown rot and other diseases.
Ensuring Long-Term Establishment
The first full growing season is dedicated to root establishment, and care should focus on consistent moisture rather than feeding. Fertilization is not recommended in the first year, as it can push tender top growth that stresses the undeveloped root system. Once established, apply a balanced, slow-release fertilizer in late fall or early spring, placing it around the drip line. This encourages root growth during the cooler months.
Pruning should be minimal in the first couple of years, but young boxwoods benefit from a technique called thinning to promote maximum density. Thinning involves selectively reaching into the shrub and removing a few interior branches to allow sunlight and air to penetrate the center of the plant. This practice prevents the outer layer of foliage from becoming too dense and shading out the interior, which can cause the center to become bare.
In colder zones, boxwood is susceptible to winter burn, a condition where foliage loses moisture faster than frozen roots can replace it. Planting in a location protected from harsh winter winds helps mitigate this risk. Also ensure the shrub is well-watered going into late fall before the ground freezes solid. Consistent, attentive care during establishment ensures the boxwood develops a healthy root system.