With the holiday season upon us, the temperatures quite cold, the leaves all on the ground, and the official start of winter just days away, my attention is drawn to the anchors of the garden: evergreens.
Often outshined by their showier and flowerier relatives in the garden during the warmer months, winter is the time when evergreens emerge and announce their presence. Perhaps because we are drawn to the color green when so much else in the landscape is dominated by browns and grays, or because their shapes and textures are so pleasing to our eyes, no one can deny that beautiful evergreen plants decorate the garden shape.
My love of conifers and hollies began with my first job out of college at the United States National Arboretum in Washington, D.C. I was assigned to work on the Gotelli Conifer Collection, which includes over 800 species of conifers, complemented by swathes of rhododendrons, crape myrtles, grasses, and Perennials. I had no idea there could be so many different colors, shapes, forms and textures. Since then, I have particularly valued conifers and other evergreen plants as an integral part of every garden design.
Here are three of my favorite evergreen trees, along with excellent selections of each type.
Although I have a fondness for plants native to eastern North America, the first evergreen tree I recommend is Juniperus virginiana, or “Emerald Guardian.” Ideal for smaller gardens due to their compact and dense form, this selection of Easter red cedar grows to only 15 feet tall and about 7 feet wide at maturity. Emerald Sentinel's foliage is dark and glossy green, which contrasts beautifully with the powder blue juniper berries. The fruit attracts cedar waxwings and a variety of other winter songbirds, some of which may even stay and build a nest in the dense branches. It prefers full sun to produce its best leaves and fruit and is drought and salt tolerant once established.
What better tree to decorate the hallways with than the American holly? Long associated with the Christmas season, the first Europeans to land on these shores were delighted to find American holly and quickly added it to their holiday decorations as a sign of the season. It was one of George Washington's favorite trees, and several still survive that he planted at Mount Vernon in Virginia. Holly lovers have bred and selected many varieties, with over 1,000 named to date. Holly trees are dioecious, indicating separate male and female plants. In order for berries to form, there must be one female and at least one male plant nearby. The following recommended varieties are all females. So consider including a male holly such as Ilex opaca, “Jersey Knight.” Ilex opaca '“Greenleaf” is a classic variety that takes on a perfect pyramid shape and only grows to 20 to 25 feet tall, making it well suited to smaller spaces. The foliage is prickly, dark green and particularly deer-resistant. It tolerates a wide range of soil conditions other than wet or waterlogged.
Japanese umbrella pines are wonderful and unusual conifers for our region; Their shapes and texture are significantly different from those of other more popular evergreen trees and are unique. The tree gets its name from the umbrella-like whorl of thick green needles that appear at the ends of the branches. In Japan, this tree can reach a height of 90 feet, but in cultivation it reaches less than half its size, about 30 to 35 feet. Sydney Waxman of the University of Connecticut has selected several excellent forms of this tree, two of which I will mention here. Firstly, Sciadopitys verticillata 'Winter Green', which reaches a height of 20 feet and almost the same width and has a very attractive, narrow pyramidal shape. The young branches are quite flexible, but if there is heavy snow accumulation I would recommend chipping away the snow. Waxman's second selection is called Sciadopitys verticillata “Joe Kozey” and is known for its narrower, upright habit. It grows the same height as Winter Green but is only 6 feet wide.
If you want to learn more about conifers and hollies, the American Conifer Society and the Holly Society of America are a good place to start. For readers in the Boston area, the Arnold Arboretum has an exceptional collection of conifers. I wish everyone a merry Christmas season full of warmth, family, friends and plants!
Uli Lorimer is director of horticulture at the Native Plant Trust in Framingham. Submit your gardening questions along with your name/initials and hometown ulorimer@nativeplanttrust.org for possible publication. Some questions have been edited for clarity. Subscribe to Globe's free real estate newsletter at Boston.com/address-newsletter.