Boxwood shrubs have long been a favorite for creating formal, structured plantings in landscapes. These dense, broadleaf evergreens provide year-round color and a sense of permanence. Their small, glossy leaves and natural density make them highly versatile for forming low borders, intricate parterres, or substantial privacy screens. Developing a successful boxwood hedge requires careful preparation and execution to ensure these long-lived plants establish a strong foundation. This guide outlines the necessary steps to transform individual shrubs into a cohesive, manicured hedge.
Planning Your Boxwood Hedge
Selecting the right variety for your climate and desired final size is the first step toward a successful hedge. Boxwoods, belonging to the Buxus genus, offer hundreds of cultivars, with hardiness zones ranging from USDA 5 to 9. For colder regions, cultivars like ‘Green Velvet’ or ‘Wintergreen’ are recommended for their cold tolerance. Larger hedges might utilize varieties of Buxus sempervirens, commonly known as American Boxwood.
Site assessment is important, as boxwood are sensitive to poor drainage. The soil must be well-draining to prevent root rot, and testing the drainage beforehand is advisable, especially in heavy clay soils. Boxwoods tolerate a range of soil types, from slightly acidic to slightly alkaline (pH 6.5 to 7.5). Light requirements are flexible, ranging from full sun to partial shade, but afternoon shade is beneficial in hotter climates to prevent leaf scorch.
Once the site and variety are chosen, calculate the correct spacing to achieve a solid, uniform hedge. The standard recommendation for a dense hedge is to space the plants at approximately half of the variety’s mature width. For example, if a variety spreads four feet wide at maturity, the centers should be spaced two feet apart. Planting them closer encourages the shrubs to grow together quickly. Measuring the hedge length and dividing it by this spacing determines the number of plants needed.
Planting Techniques for Immediate Success
Preparing the planting area begins with establishing a straight line using stakes and a taut string line. For a continuous hedge, digging a trench is often more efficient than digging individual holes, ensuring uniform soil preparation and alignment. The trench should be at least twice as wide as the root balls, but only as deep as the root ball itself.
Incorporating organic matter like well-aged compost is beneficial, especially if the native soil is poor or compacted. This amendment helps improve both drainage in clay soils and water retention in sandy soils. Planting depth is key: the boxwood crown, where the stem meets the roots, must be set slightly above the surrounding grade to allow for settling. Aim to position the top of the root ball about one-eighth to two inches higher than the finished soil level.
Before placing the plants, gently loosen any roots that are tightly circling the root ball to encourage outward growth. Backfill the trench with the prepared soil mixture, tamping gently to eliminate large air pockets without overly compacting the soil. Once all plants are set, provide a deep initial watering to thoroughly soak the entire root zone and settle the soil.
The final step is applying a protective layer of organic mulch, such as shredded bark or wood chips, two to three inches deep across the planting area. This mulch layer helps regulate soil temperature, conserves moisture, and suppresses competing weeds. Ensure the mulch does not directly touch the base of the stems, as this can trap moisture and encourage disease development.
Essential Care and Shaping
After initial planting, the first few years focus on establishment, requiring consistent moisture to develop a robust root system. During the first growing season, especially in dry periods, provide about one inch of water per week to keep the soil evenly moist. Once established, boxwoods are relatively drought-tolerant, but they benefit from deep watering during extended dry spells, particularly in late fall before the ground freezes to prevent winter desiccation.
To maintain the dense, formal look of a hedge, a regular pruning schedule is necessary. The best time for main structural pruning is in late winter or early spring, just before the plant breaks dormancy. Light, corrective shearing can be done in early summer after the first flush of new growth has matured to maintain a crisp line. Avoid pruning in late summer or early fall, as the new growth stimulated will not have time to harden off before the first frost, leading to winter damage.
When shaping the hedge, practice tapering, where the hedge is kept slightly wider at the bottom than at the top. This profile ensures that sunlight reaches the lower branches, preventing them from thinning out and becoming bare. Thinning out some interior branches with hand pruners, known as pick pruning, helps increase air circulation and light penetration. This is a preventative measure against fungal diseases like Boxwood Blight.
Established boxwoods do not require frequent feeding, but a balanced, slow-release granular fertilizer can be applied in late fall or early spring. Regular inspection is the first line of defense against pests and diseases, such as the Boxwood Leafminer or the more serious Boxwood Blight, a fungus that causes dark leaf spots and rapid defoliation. Maintaining good air movement through thinning and using mulch are cultural practices that contribute to the long-term health of your hedge.