Juniperus

Chinese juniper (Juniperus chinensis) is a species almost nobody actually plants. Missouri Botanical Garden says as much outright - species plants are rarely sold in commerce - and what garden centres stock instead is a hundred-plus cultivars spanning everything from ankle-high groundcover to 50-foot column: 'Blue Point', 'Kaizuka', 'Sea Green', 'Hetzii', the Pfitzer group. Several of those are not even this species. The Pfitzer plants are Juniperus x pfitzeriana, a hybrid with the toxic J. sabina, sold under the J. chinensis name for decades. The wild plant behind all of it is a dioecious East Asian conifer, usually a conical tree 40 to 50 feet tall and 15 to 20 feet wide, carrying two kinds of leaf at once - sharp awl-like juvenile needles 0.2 to 0.4 inches long and blunt adult scales 0.06 to 0.12 inches long - and blue-black berry-like cones 0.3 to 0.5 inches across that take roughly 18 months to ripen on female plants. It is genuinely tough: deer, drought, dry soil, shallow rocky soil, black walnut and city air are all on Missouri Botanical Garden's tolerance list. It is also genuinely dangerous to an orchard. Chinese juniper is the telial host of Japanese apple rust (Gymnosporangium yamadae) and Japanese pear rust (G. asiaticum), both now recorded in North America, alongside the cedar-apple rust group Missouri Botanical Garden names in its problems list. The juniper shrugs the rust off with a few gelatinous orange horns. The apple, crabapple, pear or hawthorn downwind does not.

Common juniper (Juniperus communis) has the largest natural range of any woody plant on earth. Missouri Botanical Garden calls it "the most widespread conifer growing in the world today", and the WGSRPD range mapped in this record runs to 130 botanical countries: a circumboreal band right around North America, Europe and Asia that reaches inside the Arctic Circle, plus one stranded population in the Atlas Mountains of North Africa. Its second claim is in the drinks cabinet. The waxy blue-black "berries" are fleshy seed cones rather than fruit, and they are the botanical that makes gin gin - the spirit category is legally defined by juniper being the predominant flavour, in EU spirit-drink law and in the US standards of identity alike. The honest caveat is that none of that makes it a good bet in most American gardens. MBG records "superior tolerance for cold temperatures and superior intolerance for heat and humidity" and states plainly that it is not recommended for planting south of USDA Zone 6, and it also notes that species plants are rarely sold in commerce - what a garden centre stocks is cultivars. Settle the habit question before buying, too, because the same species is a 9-to-12-inch prostrate mat on an exposed ridge, a 5-to-15-foot multi-stemmed shrub through most of the US, and occasionally a 45-foot tree.

Creeping juniper (Juniperus horizontalis) is the flattest thing in a genus that also makes narrow trees, and it is almost certainly the most over-planted evergreen in North American landscaping. Missouri Botanical Garden puts it at 6 to 18 inches tall spreading 4 to 10 feet wide - a true prostrate mat of trailing branches, not a low shrub - and it is genuinely excellent at the job it was bred for: holding a hot, dry, sunny bank on shallow rocky soil where a lawn would fail. Over a hundred cultivars exist, and that abundance is the problem. It gets specified as though it were a groundcover in the general sense, then walked on, sheared into a shape, or crowded against a path, and it tolerates none of those. Juniper does not resprout from bare old wood, so every broken stem, shearing cut into brown wood and shaded-out patch is permanent: the dead spot in the middle of a mat stays a dead spot. Two more things separate it from expectation. It is intolerant of wet soil - the opposite of the tolerance people assume from a tough plant - and it is dioecious, so the dark blue waxy "berries" are fleshy seed cones borne only by female plants with a male nearby, and MBG notes they are often absent altogether on cultivated stock.

A tough, aromatic native conifer of eastern North America - actually a juniper, not a true cedar - with scale-like evergreen foliage and a broadly conical to columnar form. Missouri Botanical Garden calls it the most drought-resistant conifer native to the eastern U.S., thriving on limestone glades, fence rows, and abandoned fields. It is dioecious: female trees carry the powdery blue, berry-like cones that gave the cedar waxwing its name and feed many birds and small mammals through winter.

Rocky Mountain juniper (Juniperus scopulorum) is the western counterpart to eastern redcedar, and the two are confused constantly - with good reason, because where their ranges meet across the Great Plains they hybridise freely and intermediate trees are genuinely hard to name. Start with the caveat: Missouri Botanical Garden has no species-level page for it at all, only cultivar entries, and the species is the wrong plant for a hot humid climate. The Lady Bird Johnson Wildflower Center is blunt about it - drought and salt spray are fine, high humidity and high night temperatures are not - so this is a plant for the dry interior west and the plains, not the Southeast. What it offers there is unusual. It is a narrow, slow, drought-hard tree of dry rocky foothills, 30 to 50 feet on a good site and often far less, with shredding red-brown bark, blue-grey scale foliage, and high tolerance of caliche and limestone - the mirror image of the acid-soil hollies in this batch. It is dioecious like them, so the waxy blue-black cones appear only on female trees with a male nearby, and those cones are cones rather than fruit, taking about 18 months to ripen. It also lives an extraordinarily long time: the Jardine Juniper in Utah is over 1,500 years old and a New Mexico specimen counted 1,888 rings. The hard restriction is cedar-apple rust, for which it is an alternate host - do not plant it near an orchard.