Juniperus procumbens aka Creeping Juniper

Juniperus procumbens is a low-growing, prostrate shrub reaching only 6-24 inches (15-60 cm) in height but spreading 10-15 feet (3-4.5 m) wide over time. Growth is slow, typically taking about 10 years to reach a 10-foot spread. The trailing branches grow parallel to the ground, forming a dense, mat-like groundcover. This compact growth habit makes it ideal for rock gardens, cascading over walls, and especially popular for bonsai cultivation.

Juniperus procumbens is remarkably cold-hardy, tolerating temperatures as low as -30°F (-34°C), making it suitable for USDA Zones 4-9. Ideal growing temperatures are 60-70°F (15-21°C). During winter, the foliage may turn purplish-brown as a natural frost protection mechanism but will return to normal green in spring. This species requires a winter dormancy period and cannot thrive in consistently warm climates without cold seasons.

In spring, resume regular watering and begin fertilizing as growth starts. Summer requires more frequent watering during hot, dry periods and is the best time for pruning and shaping. In autumn, reduce fertilizing and prepare the plant for dormancy. Winter care is minimal—the plant requires a dormancy period of approximately three months in cold conditions. Protect container plants when temperatures drop below 15°F (-10°C). Foliage may turn purplish-brown in winter, which is normal frost protection.

Juniperus procumbens must be grown outdoors—it cannot survive as an indoor plant. Native to southern Japan and Korea, it thrives in full sun with good air circulation. It's hardy in USDA Zones 4-9, tolerating temperatures from -30°F to hot summer conditions. Plant in a location receiving at least 6 hours of direct sunlight daily. It excels in rock gardens, as groundcover, or cascading over retaining walls. The species tolerates urban pollution, drought, and poor soils once established.

Prune in late winter or early spring at the end of dormancy. For maintenance, pinch back new growth using your thumb and index finger rather than scissors to maintain compact foliage—using scissors on needles causes browning. Remove dead, damaged, or crossing branches with clean pruning shears. Thin out dense interior foliage to prevent pest problems and improve air circulation. This species tolerates severe pruning and can be shaped extensively for bonsai. Avoid removing all new growth; always leave some to maintain plant health.

Repot young junipers (under 10 years) every 2-3 years, and mature specimens every 4-5 years, always in early spring before new growth begins. When repotting, remove the outer and bottom quarter of the root mass—never prune more than one-third of roots at once. Use well-draining soil and work it carefully around roots to eliminate air pockets. After repotting, water thoroughly by submerging the pot, then protect from wind and direct sun for 1-2 months. Wait at least 4 weeks before applying fertilizer.

The most reliable propagation method is semi-hardwood stem cuttings taken in late winter or early spring. Take 4-6 inch cuttings, remove the bottom third of foliage, dip in rooting hormone (gel works best), and plant in a sterile mix of equal parts sand and peat or perlite. Keep in bright indirect light with high humidity using a plastic tent. Roots emerge in 4-6 weeks but may take 6 months to develop fully. Transplant when roots reach 3 inches. Layering is also effective—bend a branch to the ground and cover with soil until roots form. Seed propagation is not recommended as berries are rarely produced.

Common pests include spider mites (especially in dry conditions), aphids, bagworms, twig borers, scale, and webworms. Spider mite infestations cause yellowing foliage and weakened plants. The primary disease concerns are Phomopsis twig blight (causing dieback of stem tips), rust diseases, and root rot in poorly-drained soils. Dense foliage can harbor pests, so thin out crowded growth regularly. Prevent problems by ensuring good drainage, adequate air circulation, and avoiding overhead watering. Inspect regularly and treat infestations promptly with appropriate insecticidal soaps or horticultural oils.

The most popular cultivar is 'Nana' (Dwarf Japanese Garden Juniper), a compact form reaching only 8-18 inches tall with dense, mounding growth—this is the most widely used variety for bonsai. 'Greenmound' is even more compact at just 8 inches high with lighter green foliage. 'Bonin Isles' has a mat-forming habit. 'Variegata' features attractive gold streaking on its foliage. 'Kishiogima' displays multi-colored foliage with seasonal color changes. All varieties share the species' prostrate habit and require similar care.

Juniperus procumbens is dioecious, meaning individual plants produce either male or female cones, not both. As a conifer, it relies on wind pollination rather than insects. Female plants produce small, fleshy seed cones (resembling blackish berries) about 8-9 mm in diameter, typically containing three seeds. However, berries are often absent on cultivated plants, especially the popular 'Nana' variety. For berry production, both male and female plants must be present. The inconspicuous cones are not a significant ornamental feature.

Juniperus procumbens has aromatic foliage typical of junipers. The needles release a fresh, resinous, slightly spicy scent when crushed or brushed against. This fragrance comes from terpenes in the foliage—the same aromatic compounds found throughout the Juniperus genus. The scent is noticeable but not overpowering, adding sensory interest to gardens or when working with bonsai specimens. Some people find the juniper fragrance pleasant and reminiscent of gin (which is flavored with juniper berries from related species).

Yellowing foliage on Juniperus procumbens typically indicates stress from spider mites, overwatering, or poor drainage. Spider mites are a common culprit—inspect the underside of needles for tiny pests and fine webbing. Overwatering or waterlogged soil causes root rot, leading to yellow and dropping foliage. Other causes include nutrient deficiency, insufficient sunlight, or being kept indoors (this species cannot survive as a houseplant). Address the underlying issue: improve drainage, reduce watering, treat pests, ensure outdoor placement with full sun, or fertilize during the growing season.

Brown foliage on Juniperus procumbens can indicate several problems. Tip and twig blight (often Phomopsis) causes browning of branch tips—prune affected areas back to healthy growth. Spider mites cause needle browning and dieback. Drought stress or extreme heat can brown foliage, as can root rot from poor drainage. Winter browning (purplish-brown) is normal frost protection and will resolve in spring. Indoor placement causes irreversible browning as this species cannot survive indoors. If browning is localized, prune affected areas; if widespread, investigate root health, watering practices, and check for pests.

Juniperus procumbens does not produce true flowers. As a conifer (gymnosperm), it produces cones rather than flowers. Male plants produce small, inconspicuous pollen cones, while female plants produce seed cones that develop into small, fleshy, berry-like fruits about 8-9 mm in diameter. These 'berries' are actually modified cones with fleshy scales. However, in cultivation, especially with the popular 'Nana' cultivar, cones/berries are rarely produced and are not a significant ornamental feature. The primary appeal of this species is its elegant evergreen foliage and spreading habit.

Spray foliage with water daily during the growing season to maintain humidity and wash away dust and pests. Thin out dense interior foliage regularly to prevent pest infestations and improve air circulation—overly dense growth harbors spider mites and other pests. Remove any dead, brown, or yellowing needles and branches promptly. For bonsai specimens, gently brush or pick out debris that accumulates in the foliage. Avoid using leaf shine products on conifers. Good air circulation is essential, so don't crowd plants together and ensure adequate spacing for airflow.

Juniperus procumbens is primarily valued as an ornamental plant with several landscape uses. It's the most popular species for bonsai in the United States, prized for its graceful cascading habit and adaptability to training. In landscapes, it excels as groundcover, forming dense mats that suppress weeds on slopes and banks. It also tolerates urban pollution well.