Juniper Trees

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Junipers get no respect. Some folks laugh to see them tightly pruned to pompons out on the Avenues of San Francisco; most of us just ignore them as background landscape noise. Even in better neighborhoods you see juniper hedges festooned with spider webs, or groundcover plantings of junipers baking and miserable, transplanted during California’s last drought, now patchy and ragged from lack of care and lack of irrigation.

Take another look at these useful evergreens — the ones you may have in your garden and those you find at a local garden center. Does your mixed border need a backbone shrub? Would you like a tall spire accent for your front yard? Have you got a terraced hillside to fill? By all means, explore junipers in their wide range of colors and forms.

California has several native junipers, long-lived denizens of high desert and hot-zone foothills where you find digger or pinon pines. In nature they grow as multi-trunked small trees, often with twisty trunks of great character. J. californica() and the blue-tinged Sierra juniper, J. occidentalis, are rarely used in landscaping. Sometimes wild trees are dug up (with permits, of course) and transplanted as a single picturesque specimens in a desert-themed landscape or Japanese garden.

The spreading mat juniper, J. communis saxatilis, is easier to find, and makes a fine, drought-tolerant groundcover if you’re looking for a native plant to range over a rocky bank. Less than a foot tall, mat juniper has green needles with a silvery reverse, and fleshy blue fruits that resemble trapezoid blueberries.

Most of the groundcover junipers at the garden center are variations of J. horizontalis , an alpine native to the chillier regions of North America. There are lots of pretty colors–bold yellows, powdery blues, even a few that turn a pretty purple tint in winter (‘Bar Harbor’). With feathery branches trailing and creeping, these junipers are drought-hardy, and excellent choices for a rock garden or terraced planting. Unfortunately we often see poor J. horizontalis planted in baking-hot sites; eventually the plants lose their leaves, leaving bare, spindly stems along the ground. These actually prefer a bit a light shade in summer, though in fog zones they will take what sun you can give them. A little summer water doesn’t hurt either. Given good drainage and a gravely planting bed, you might use them in a mixed border that features other low evergreens, such as dwarf spruce and mugho pine.

If you’re looking for a hedge plant, many varieties of Chinese garden juniper, J. chinensis, will suit you. Shrubbier sorts such as San Jose, Hollywood, and Pfitzer are the common ones sheared to lollipops, pillows and pompoms. It’s a testament to how well junipers as a group respond to hard or frequent pruning–an old, rangy foundation plant can be rejuvenated by cutting it back hard in early spring. Prickly Chinese junipers make good barriers; if you’d like a softer hedge, look for plants with elongated scaly foliage, not needle-type.

Another point to remember is if you’re looking for a tall hedge, choose J. chinensis varieties that grow upright; many with golden or blue-toned foliage never get higher than two or three feet. Upright, columnar varieties make nice, tight spires that can merge into a hedge or be planted as tall garden accents, standing in for a water-thirsty yew or slower-growing cypress.

Browned tips on junipers are danger signs. If the tips are brownish black and soft, that’s root rot, caused by giving the plant too much water. Stop watering immediately and the plant may recover; trim off the dark tips. If browned patches on junipers are stiff and hard, the culprit is usually the larvae of a tip moth. Break open the tip and you may find it hollow — or spot the nearly-microscopic brown worm wriggling within. Bt sprays (Bacillus thuringiensis) are an organic treatment to kill the grubs.

Landscapers like junipers because they are nearly maintenance-free, and if you choose them well they can be solid backbones of your garden design. But don’t ignore them, and by all means sweep them of cobwebs now and then.