If you're thinking about adding conifers to your landscape, be sure to consider your climate before you buy. I asked experts in different regions to name the best performers in their conditions. Here's what they recommended.
At the U.S. National Arboretum, conifers intermingle with crape myrtle cultivars, Japanese maples, and many ornamental grasses. "One of my favorites," Martin says, "is an old creeping juniper cultivar, 'Douglasii', which is a soft powdery blue color with a growth habit loose enough to allow bulbs to grow through it." She also appreciates drought-tolerant junipers and pines that can stand up to the summertime heat and humidity of the Northeast. "We can grow almost all the spruces, arborvitae, and false cypresses as long as they have ample soil moisture."
"Junipers are underused here in the South, yet some are very exciting in both color and habit," says Sam Jones, Ph.D., of the University of Georgia. Two that Dr. Jones likes are 'Horstmann', an upright green juniper with a loose, weeping character, and 'Blue Forest', a sprawling carpet of blue-green foliage only 10 inches high. (Dr. Jones and his wife also maintain a 3-acre display garden and grow 450 different species of coni- fers at Piccadilly Farm Conifer Garden, their retail nursery in Bishop, Georgia.) The gold threadleaf sawara cypress is a regional favorite, he says. Japanese plum yews also do well, tolerating both heat and shade. But spruces, firs, and tiny false cypresses don't fare as well.
Spruces are some of the best dwarf conifers for this climate, according to Vanessa Mueller, horticulturist at Rich's Foxwillow Pines Nursery, in Illinois. "There are so many wonderful cultivars, and they are great choices for the novice gardener," she says. A Colorado spruce with fabulous color is 'Thuem' (sold also as 'Thume'), a mounding conical form with magnificent blue color. White pines also do well in the Midwest, but firs, accustomed to a cooler climate, are more challenging. Yet they're fast becoming collectors' plants, particularly the Fraser and Korean firs, Mueller reports. Most important to success with these and all conifers is correct planting. "Find the trunk flare (where the trunk gently flares out to the top of the root), plant the tree high, and mulch," Mueller prescribes.
While some cedars fare well in this climate and junipers easily hold their own, Pat Hayward, horticultural editor at Garden Railways magazine, says her top pick for the northern regions of the Southwest are pines. Hayward, who also teaches conifer classes at the Denver Botanic Garden, says the two- and three-needle pines (the needles on pines are grouped in clusters of either two, three, or five) adapt well to the region's drier conditions and alkaline soil. Mugo pines do especially well. "'Pot o' Gold' turns gold in winter," Hayward says. Another exciting pick is lacebark pine, with its fascinating grayish green exfoliating bark. "In Colorado, we're finding them more drought-tolerant than we had thought."
Living in Oregon, where native conifers abound, I'm fortunate to be able to grow most any evergreen I please, and there are many that please me. I've become especially fond of the weeping and upright types. Lucky for me there's 'Pendula', an outstanding upright weeping white spruce with blue-green needles that combines both forms. I'm still wondering where to put it, but I have found just the spot for my low-growing 'Procumbens' Colorado spruce.