The Blue Arrow Juniper (Juniperus scopulorum ‘Blue Arrow’) is a highly sought-after evergreen known for its exceptionally narrow, columnar growth habit and striking silvery-blue foliage. This cultivar stands tall, typically reaching 12 to 15 feet in height but spreading only 1 to 2 feet wide, providing a powerful vertical element in the landscape. Selecting appropriate companion plants involves finding species that not only enhance this architectural form but also share its specific environmental needs. Successful pairing relies on understanding the juniper’s requirements for sun exposure, soil composition, and water availability to create a cohesive and low-maintenance planting scheme.
Establishing the Required Growing Conditions
The most fundamental requirement is a minimum of six hours of direct, unfiltered sun each day; insufficient light will compromise the juniper’s dense habit and vibrant blue coloration. All companion plants must be highly heat-tolerant to prevent scorching or wilting during peak summer months.
The second, non-negotiable factor is soil drainage; the juniper is extremely intolerant of standing water or persistently wet roots. It naturally thrives in lean, rocky, or sandy soils that drain rapidly, making excellent porosity a universal requirement for the entire planting area. This preference for quick drainage means that the soil pH can be slightly acidic to neutral, but the texture must prevent waterlogging.
Once the Blue Arrow Juniper is established, it becomes highly drought-tolerant, relying on deep, infrequent watering. Therefore, companion plants must also be water-wise, ideally requiring minimal supplemental irrigation after their first year in the ground. This prevents the overwatering that could lead to root rot in the juniper.
Low-Growing and Groundcover Companions
Groundcovers anchor the juniper’s vertical line while covering the soil to suppress weeds and reduce moisture evaporation. Creeping Junipers, such as Juniperus horizontalis ‘Blue Forest’ or ‘Copper Harbor,’ provide excellent textural contrast, juxtaposing the ‘Blue Arrow’s’ fine, upward-pointing needles with a flat, horizontal mat. ‘Copper Harbor’ offers seasonal color shifts, displaying yellow-gold foliage in summer that deepens to copper tones in the winter.
Sedums are ideal drought-tolerant partners that add a contrasting texture and form. Varieties like Sedum reflexum ‘Blue Spruce’ feature fine, needle-like blue-green foliage that echoes the juniper’s color but with a soft, spreading habit. For a vibrant contrast, Sedum ‘Angelina’ provides chartreuse-yellow foliage that can turn bronze in full sun, spreading quickly over rocky terrain.
Creeping Thyme (Thymus praecox) is an excellent choice for sharp-draining areas, forming a dense, low-growing mat only a few inches high. Cultivars like ‘Coccineus’ produce a carpet of small, magenta flowers in late spring, creating a burst of color at the juniper’s base. This durable plant handles light foot traffic and thrives in the lean, well-draining soil required by the juniper.
For a fine-textured, mounding effect, Blue Fescue (Festuca glauca) is a clumping ornamental grass that maintains a compact, dome shape of silvery-blue foliage. This small grass, typically 8 to 12 inches tall, repeats the blue color of the juniper but with a delicate, linear texture. Planting it in full sun is necessary to ensure the foliage develops its characteristic slate-blue hue rather than reverting to a greener shade.
Mid-Height and Flowering Perennial Companions
Mid-height companions provide a visual transition, linking the ground plane to the juniper’s towering height while introducing seasonal color. Russian Sage (Perovskia atriplicifolia) features silvery-gray foliage that complements the juniper’s blue and clouds of lavender-blue flowers from mid-summer into fall. This sub-shrub typically reaches 3 to 5 feet tall and provides an airy, soft texture that contrasts sharply with the juniper’s rigid, dense structure.
Yarrow (Achillea) is a sun-loving perennial known for its finely dissected, fern-like foliage and flat-topped flower clusters. It is highly tolerant of dry conditions and poor soils. Varieties like ‘Coronation Gold’ (yellow) or ‘Paprika’ (reddish-pink) offer warm color contrasts against the juniper’s cool blue, blooming reliably throughout the summer months.
To introduce vertical repetition with a softer movement, the narrow, upright form of Feather Reed Grass (Calamagrostis x acutiflora ‘Karl Foerster’) is an excellent choice. This cool-season grass forms a tight clump only 1.5 to 2.5 feet wide, sending up stiff flower plumes that can reach 5 to 6 feet tall. The sterile plumes emerge pinkish-purple before aging to a persistent, golden-tan color that provides structure and texture throughout the winter.
Purple Coneflower (Echinacea) cultivars are drought-tolerant perennials that provide a sturdy, upright flower form and attract pollinators. These plants thrive in the same full-sun, dry-soil conditions as the juniper and offer a bright, daisy-like flower shape. Choosing varieties that top out around three feet ensures they provide mid-height interest without competing with the juniper as the primary vertical focal point.