This extremely adaptable, low-maintenance groundcover isn’t fussy about growing conditions, and its blue-green needles discourage deer browse and bring a cool, calming element to the landscape. It reaches 6-18" tall and 10’ wide in a variety of well-drained soils and hot, sunny climates, but it also withstands snow and sub-zero temps. It requires consistent moisture during the first year as it establishes its root system; after that, it only needs water during long drought spells. Too much water or shade can lead to root rot or fungal disease. Creeping juniper is found in rocky or sandy soils of outcrops or streams throughout Canada and the northern US. The species and common names refer to the horizontal growing habit of the long, trailing branches that are capable of spreading by layering, which happens as the low-lying branches form new roots. Like other junipers, it produces cones to facilitate reproduction. As the cones mature, they become fleshy and blue, and the scales are so tightly compacted that the cones resemble berries.
Junipers have a long history of medicinal and culinary use in their native ranges of North America, Europe, and Asia. People in the Middle Ages believed the plant could ward off diseases and infections, and Native Americans used them to treat a plethora of symptoms. Francis Sylvius, a 17th-century Dutch physician, created a medicinal tonic from juniper cones; it took Europe by storm as people discovered the pleasurable properties of the inexpensive medicinal we now call “gin.”
Because the 60-some species of junipers contain different levels of thujone, a toxic ketone, extreme caution should be taken before consuming junipers in the wild. Juniperus communis is the variety most often used to make medicines and food dishes, and creeping juniper (J. horizontalis) is also considered to be edible. The cones taste strong, bitter, and slightly peppery, making them suitable for flavoring meats, sauerkraut, and other dishes. The outer dusting of the cone is actually a wild yeast, which people have used to make beer and breads, especially sourdough recipes. For more details on medicinal and culinary uses, refer to Gardening Know-How (https://tinyurl.com/5xwcxrz)s and Naturewithus (https://tinyurl.com/32he35ue).
Native habitats include banks of streams, rocky outcrops, sandy dunes or pastures, and cliffs. Creeping juniper is perfect for rock gardens or walls, slopes and banks, mass plantings, and drought-tolerant gardens. It helps with erosion and is tolerant of salt and urban conditions.
Plant Characteristics:
Grows 6-18" tall and 8-10’ wide.
Requires at least 6 hours of full sun. Tolerates hot, arid climates.
Prefers sandy or rocky soils with somewhat dry to average moisture but adapts to a wide range of well-drained soils, including loam and clay-loam. Tolerates drought and poor, dry, compacted, or acidic soils.
Produces cones at the tips of shoots in spring, two years after pollination. Male cone is 1/10 - 1/8” long with a cluster of yellow stamens. White to pink female cone is a cluster of scales around half that size. Mature cone is globoid in shape and light blue with a glaucous coating. Stiff, resinous pulp contains 1-3 seeds.
Scale-like, lanceolate-shaped leaves are closely pressed to the stem and arranged in 4 partially overlapping ranks. Leaves are evergreen and may turn pale reddish purple during winter.
Bark is reddish brown and peeling. Branchlets are smooth and brown, and new growth is yellowish green.
Reproductive System: Male and female parts grow on different plants (dioecious). One of each is required to produce viable seeds. Cones are cross-pollinated by the wind.
Wildlife Value:
The genus Juniperus is host to several species of Lepidoptera larvae, including gray hairstreak and cassius blue butterflies. Various insects feed on the plant. The cones are eaten by turkeys, cedar waxwings, American robins, and several other bird species. Deer may browse on the evergreen foliage when food is scarce.
Medicinal, Edible, and Other Uses:
The cones have antiseptic, anti-inflammatory, and anti-viral properties.
Native Americans used juniper berries to flavor wild game, cakes, and breads. Small quantities of mature juniper berries are added to marinades, meat rubs, pickled meats, and wood chips as a flavoring or spice.
Juniper berries are added to hair rinses, vinegars, or oils to promote shiny hair.
Caution: All juniper cones varying levels of thujone, which can cause stomach upset, diarrhea, and kidney problems when ingested in large quantities. Juniper cones are not considered safe for pregnant or nursing women. Handling juniper plants can irritate skin; gloves are advised.
Resources:
Butterflies: https://tinyurl.com/4w9bkd8d
Illinois Wildflowers: https://tinyurl.com/4f8ruexu
The Spruce: https://tinyurl.com/53ezcsxe