Solving a conifer conundrum
Where to buy or browse
3Check with local garden centers, which might be able to order plants not in stock. Forestfarm, a mail-order nursery in Williams, Ore., has most of the rare conifers mentioned, in various sizes. They can be ordered now for early spring shipment. Call 541-846-7269 or visit www.forestfarm.com .
3To view rare and mature specimen conifers for the Washington garden, visit the National Arboretum's Gotelli Conifer Collection. 3501 New York Ave. NE. 202-245-2726. www.usna.usda.gov . Free.
In the season of the tannenbaum, give a thought to the idea of bestowing the garden with a permanent evergreen to admire, smell and touch while it brightens the gray winter landscape.
I am thinking a lot about choice conifers at the moment. The old American holly behind my house is showing signs of decline. Its loss would be profound: The garden around it is built on its shade, it provides important screening from the property up the hill, and its sheer size - 50 feet tall and at least 20 across - defines this corner of the garden.
It grows in curious soil, silty, organic but extremely fast-draining, and I suspect the holly's expanding trunk canker is related to drought stress over the years. It would be prudent to plant something behind it now, so that when the holly bows out, there will be a stand-in ready to go, like the show-saving ingenue in an old Hollywood musical.
An evergreen can perform two functions: as a specimen to be admired for its texture, color and form, or as a screen. For a specimen, you would pick a site with lots of room and then a handsome, fast-growing plant such as a cedar, large pine or spruce. Screens are often in tight spaces, so the evergreens in a hedge need to be slow-growing and upright, such as arborvitae or false cypress.
Here's the rub: The urge is to want immediate effect and to select specimen conifers for screening. This approach dooms homeowner and hedge to years of unhappiness, as the poor soul struggles to keep things in scale by mutilating the plants. The Leyland cypress is the obvious victim, but you can see this, too, with white pines and Norway and blue spruces.
Variety of choices
My space is a little different. There is room behind the holly for a conifer to spread its wings. This offers the lucky chance to plant a specimen that will also screen. One is spoiled for choice.
A friend grows the China fir, which is noted for its big, pointed needles, dark green cast and general exotic air. It does, annoyingly, hang on to dead inner stems, giving mature specimens a scruffy look if not groomed. It will grow to 30 feet in less than 20 years. Unfortunately, it doesn't like drought and flourishes in soil that stays moist, so it wouldn't be the best choice for my area.
I really like the Himalayan pine. The tree is upright and pyramidal, but the needles hang down in contrast: They are a lovely light green, long and showy, and quite feathery. The Himalayan pine will reach 50 feet in 30 years, with a broad spread. I read that drought causes dieback in its lower limbs, which works against its selection in my dry site.
I called the New York Botanical Garden's conifer expert, Todd Forrest, and he commends the Korean pine. This is generally praised by connoisseurs for its formal pyramidal shape, dense needles, layered habit and its keeping of lower branches in a way that the white pine does not. Why this pine species is not more widely grown is one of the gardening mysteries. It will reach 25 feet in 15 years, its rate slowing afterward.
Forrest is a big fan (as am I) of the Serbian spruce, and he likes the slender and drooping variety named Pendula.
The weeping Nootka false cypress is another handsome and pendulous tree, and well suited to the Washington heat.
The incense cedar resembles the arborvitae in its leaf texture and columnar shape but is a bigger plant and more lush. The fans of foliage keep their color in winter and shed wet snow better than most evergreens. It's a lovely, narrow conifer, though perhaps not the first choice as a supreme specimen.
I am drawn to an oldie but goodie: the deodar cedar. It is big, fast-growing, fine-textured and the softest and greenest of the three cedar species that you see in Washington. It demands a free-draining location, and I think it might be the perfect choice. The esteemed plantsman Michael Dirr planted three as a screen and later wrote: "To me, they are among the most graceful of conifers."
Imagining such a planting is the beauty of the bleak season. With the ground frozen and soil work impossible, you can mull over the best tree, read what other gardeners think of your shortlist and take your time finding a source. Pull up an armchair.
6 Follow @adrian_higgins on Twitter.