One of the nice things about conifers is that they don't dump leaves all over your yard in the fall. With the exception of larches, the bald cypress and dawn redwood, conifers -- whose name means cone-bearing -- are evergreen.
Their branches discreetly lose their leaves -- called needles or scales, depending on the type -- throughout the year but are never bare. After the deciduous trees shed their leaves in the fall, the conifers stand out in full dress.
Conifers are often the backbone of gardens as well as forests throughout the world. According to Dave Thompson, owner of Foxborough Nursery in Street, Md., conifers are multipurpose, ideal for foundation planting, hedges, rock gardens, accents or as solitary specimens. The tall full ones, such as arborvitae and white pine, buffer against noise and wind.
In ancient times, the Romans planted umbrella pines along the Appian Way so soldiers could march in the shade. The needles and bark of some conifers are used in medicines; for example, some varieties of yew are used to fight certain kinds of cancer. Pine needles make good mulch. Conifers are used in bonsai dishes.
There are six families of about 50 genera and about 500 species, and they range in size from ground-cover to almost skyscraper height. Author D. M. van Gelderen lists some 106 varieties of Lawson cypress alone in his book "Conifers." Foxborough Nurseries, a wholesale business specializing in dwarf conifers, carries about 2,550 varieties of conifers. The Baltimore-area gardener is likely to be interested in the genera of arborvitae, junipers, yews, firs, hemlocks, spruces, pines, cedars, cypresses, false cypresses and larches.
With so many conifers, it's important to know the characteristics of your site before buying a new conifer, such as its dimensions, how much growing room it has, the quality of the soil and the amount of sun it gets. Generally speaking, Thompson says, conifers need watering during dry spells, and they need sun. Hemlocks and firs are more shade-tolerant than the rest; yews can't tolerate wet feet. Anytime in the fall until the ground freezes is an excellent time to plant your conifer, as is spring. Some people buy live, balled Christmas trees and, after the holidays, plant them in a hole dug when the ground was still soft.
You'll need to consider color, speed of growth, hardiness and shape when choosing your conifer. Shades ranges from green to blue, yellow and some variegations. Examples of bluish ones are the blue-leaved Colorado spruce and the blue Atlas cedar (blue cedar); some yellow ones are the Pisifera cypress 'Plumosa Aurea' and the deodar cedar 'Golden Horizon.' The Leyland cypress 'Silver Dust' is variegated. The Latin words "glauca" and "aurora" indicate blue and yellow respectively, but not all plants are so clearly named. Always ask.
Speed of growth in conifers can vary wildly, so be sure to consult a reliable nursery person before you buy, and leave enough growing room in your site. Both Leyland and Lawson cypresses can grow a foot a year, but many, especially dwarf conifers, grow slowly.
Their shapes vary too, again more among the dwarfs. The terms "compacta," "pyramidalis," "weeping," "pendula," "creeper," "column," "horizontalis" and "globose" should be self-explanatory, but speed of growth is not always indicated on the label, and that may be the most important quality to you, so be sure to ask.
According to the U.S. Department of Agriculture's hardiness zone map of the continental United States, central Maryland has a hardiness rating of seven (out of 10), meaning that the average minimum temperature that plants can tolerate here is 0 to -10 degrees Fahrenheit. Some cedars, especially deodar cedar and cedar of Lebanon, with a hardiness rating of seven, are marginal and may experience some damage during a severe winter.
Resistance to disease and pests is another factor. Standard-size eastern hemlocks have been having a rough time lately with the woolly adelgid (a microscopic insect), but dwarf ones seem to be impervious. Juniperus virginiana, also called red cedar, is susceptible to cedar apple rust. The experts at Foxborough Nursery advise that spruces and pines are the most reliable, carefree conifers.
Other advice: Don't plant below the top of the root ball; roots grow downward, not upward. Water and mulch after planting, choosing a texture of mulch that is proportionate to the size of the plant.
Pub Date: 11/09/97