By Andrew Bunting, PHS Vice President of Horticulture
The winter months can be a challenging time in the garden. With colder temperatures and exposure to the elements, summer tropicals and ornamental annuals need to be swapped out, which creates an opportunity to get creative to maintain seasonal interest. Thankfully, the winter season does not mean you need to say goodbye to color and ornamental attributes in your garden. Conifers make an excellent choice to spruce up the winter garden, as they provide a beautiful focal point even throughout the bleakest months. Conifers have woody trunks and stems and can be low shrubs or very tall trees, and their leaves often look like needles, scales, blades, or wedges.
Below is a snapshot of many great conifers for the winter garden that can easily be found at your local nursery or garden center.
Screening conifers make an ideal choice for creating living hedges. In my own home garden, I extensively use Thuja ‘Green Giant’ for different hedging needs, giving my space privacy while looking great. In one part of the garden, I let it get about 20 feet tall where it effectively screens a two-story house. I maintain this height by pruning it yearly. There are also diminutive selections which include ‘Junior Giant,’ which reaches 15 - 20 feet tall, and ‘Baby Giant,’ only reaching 14 feet tall, with beautifully textured foliage.
Of the upright arborvitae cultivars, one of my favorites is Thuja occidentalis ‘Degroot’s Spire,’ which provides interest through its spire-like architecture. Additionally, Chamaecyparis ‘Forever Goldy’ is hardy in zones 5 - 8b, reaches 10 - 12 feet, and provides outstanding golden foliage perfect for a stunning winter specimen, or even a winter container when the plant is young. For a long time, I have been a fan of the Japanese red-cedar, Cryptomeria japonica ‘Yoshino’ as a screening tree. This specimen reaches 50 - 60 feet tall in USDA zones 6 - 8.
Of the small conifers, Juniperus horizontalis Pancake™ has dark green foliage that will turn bluish in the winter. Reaching only 12 – 18,” it is perfect for the small courtyard garden or container planting. Cryptomeria japonica ‘Black Dragon’ has dark green foliage but only reaches 12 feet tall with a spread of 5 feet. Like most cryptomerias, it is also tolerant of a fair amount of shade. Cryptomeria japonica Dragon Prince™ and Cryptomeria japonica Dragon Warrior™, are rounded, diminutive evergreen shrubs that are perfect for containers.
Selected through the Pennsylvania Horticultural Society’s Gold Medal Plant Program, Cryptomeria ‘Globosa Nana’ is a highly textured, low-growing selection of the Japanese red-cedar that is great for foundation plantings. Also a PHS Gold Medal Plant, another conifer I like is the dwarf hinoki cypress, Chamaecyparis obtusa ‘Nana Gracilis.’ This very dark green pyramidal specimen is very slow growing and thrives in most light conditions, including low light. In a shady corner it would contrast beautifully with an underplanting of the Hakone grass, Hakonechloa macra ‘Aureola’ or a chartreuse leaf Hosta, like ‘June.’ Chamaecyparis obtusa Night Light™ also has a rounded habit and striking golden foliage.
Pines make a wonderful option to provide winter interest in the garden. The white pine, Pinus strobus, remains a ubiquitous evergreen tree in many landscapes throughout the country and can get very picturesque with age, but does suffer from wind and heavy wet snow impacts. ‘Domino’ is a hybrid between the white pine and a Mexican pine, Pinus ayacahuite. Reaching only 8 feet tall over ten years, it has soft needles with a bluish cast. The lacebark pine, Pinus bungeana remains one of the best pines for amazing winter interest. Over time the bark will develop a camouflage-like look with patches of white, dark green, beige, plum, and more. Over a longer period, the bark will become increasingly a uniform alabaster white.
Entire books have been written on the junipers, and they range from groundcovers, to shrubs, to trees. A couple notable standouts include Juniperus ‘Grey Owl,’ which is thought to be a hybrid, shrub-like spreading plant. It has striking grey-blue foliage, and over time can reach 6 - 8 feet tall with a spread over 10 feet. It is a beautiful addition to the winter landscape where it makes a great combination with many of the dogwoods with colored stems such us ‘Cardinal.’ Juniperus virginiana Emerald Sentinel™ is an upright, emerald-green selection of the Eastern red cedar. This native juniper is very hardy and can tolerate a myriad of soils, as well as develop very attractive blue fruits which are a food source for bird populations.
There is not a conifer more noble and regal as the firs, Abies. However, many firs can struggle with heat and humidity, as well as poorly drained soil. The Japanese fir, Abies firma is tolerant of many of these conditions. It has bright green needles and will reach 50 - 60 feet tall. The Korean fir, Abies koreana has darker foliage and has striking, stout, upward facing blue-purple cones.
One of the most remarkable of all the conifers is the Chilean native, the monkey puzzle tree, Araucaria araucana. It has an amazing open architecture where each stem is covered in very sharp needles and would do well in sand soils like those found in parts of New Jersey. Over time, it will become upright and pyramidal with a rounded top. For seasonal winter interest they are simply stunning. Siting seems critical for the success of the monkey puzzle. They seem to like well-drained soils and enjoy being planted on areas that are sloping where excess moisture can drain away.
The above planting options offer just a glimpse of the many great conifers that can offer beautiful seasonal interest during the winter months. Be sure to visit your local nursery or garden center to see what conifers are available near you and consider how your garden’s conditions are suited to different species. With these ideas in mind, you are sure to have a stunning garden even throughout our grayest and coldest months.