The interest and versatility of these slow growers makes them attractive for residential and commercial settings
Conifers grow with such variation of habit that even of the low-growing types, the options are vast, offering a number of combinations of texture, color and height to meet a variety of landscape needs.
From prostrate to spreading, low-growing conifers can naturally fill in landscaped areas as well as provide distinct focal points in garden displays.
“As more people learn about these plants, they are specifying them more,” said Sandy Dittmar, consumer marketing representative at Iseli Nursery (Boring, Oregon), which specializes in conifers. “The demand is there.”
Defining what is a low-growing conifer can be tricky, as habit can be manipulated. For instance, a dwarf, staked conifer becomes a rambler through the understory when allowed. Nonetheless, low conifers generally can be divided into three types:
• Prostrate conifers are flat and grow along the ground without setting roots. They are more officially considered groundcovers.
• Spreading conifers, although not formally considered groundcovers, grow much wider than tall and will fill a space over time. For example, Blue Star juniper (Juniperus squamata ‘Blue Star’) spreads flatter, about 2–3 feet high by 3–4 feet wide. It is used well in the border or in mass plantings for low-maintenance landscaping
• Dwarf conifers are not groundcovers and work as individual plants but are flat, not globes, Dittmar said. They will consume a space much wider than tall. For instance, Picea abies ‘Elegans’ is a slow-growing dwarf. Its habit is a flat and wide, densely branched mound, about 2–4 feet tall and 3–4 feet wide.
“People have become more aware of the dwarf conifers in general, and see opportunities to use certain plants in a setting where they want ground-covering,” Dittmar said.
It does take some exploring, learning and understanding, though. Conifers can be a harder sell, Dittmar said, because consumers are less familiar with them than, say, a rose or a daffodil. Plus, a conifer comes in at a higher price point because it takes longer to produce.
“But they’re never going to have to buy it again; whereas, the other plant will need to be replaced,” Dittmar said.
Also, they are a natural fit for many of today’s lifestyles. They’re suitable in smaller urban lots for people with no time for maintenance and who want their plants to look good all year.
“We want an oasis, and there’s the shapes and forms of plant material with conifers to provide that,” Dittmar said.
Juniperus horizontalis ‘Mother Lode’, introduced in the early 1990s by Iseli as a sport off Juniperus horizontalis ‘Wiltonii’ (creeping juniper), is one example. It grows extremely flat, inches off the ground, with bright, golden yellow foliage that turns a rich burgundy in winter.
Juniperus communis ‘Green Carpet’ is one of Dittmar’s favorites, due to its foliage that starts out bright green and deepens to a rich green as it matures. It reaches just under a foot high and grows fairly quickly, at 3–6 inches per year. Hardy to Zone 3, it’s a good choice in dryer climates and in formal gardens.
Juniperus communis ‘Effusa’ is flat but has more of a native or natural look than ‘Green Carpet,’ Dittmar said. Thus, it is closer to the straight species while still filling an area, growing 6–8 inches a year and maturing at 2 feet high by 10 feet wide.
Picea pungens ‘Procumbens’ is a good blue spruce that sprawls. Dittmar likened it to a Colorado blue spruce that has been flattened to hug the ground. It becomes lush blue carpet of the signature frosty blue color, growing up to 8 inches a year and reaching 10 feet at maturity. Sometimes it sends up a leader, which can be pruned to allow it to continue to sprawl, filling a space nicely when paired with an upright blue spruce, Dittmar said.
Pinus strobus ‘Niagara Falls’, an Iseli introduction, has long needles with a blue-green cast that are soft to the touch, Dittmar said. The plant cascades and flows with a natural look that fills a space quickly, she said, growing 6–8 inches a year and maturing at 6 feet tall and 10 feet wide.
Another taller, quickly spreading conifer, Pinus sylvestris ‘Albyn Prostrate’ (a Scotch pine), has a thicker, courser needle, a stiffer appearance and a blue cast on thick green needles, giving it a deep, rich look.
Additionally, Tsuga heterophylla ‘Thorsen’s Weeping’ is a western hemlock often seen as staked and weeping. If not staked, Dittmar said, it will grow horizontally, about 3–6 inches per year, with deep emerald soft-looking branches.
Easy growing, Easy care
Low-growing conifers usually do not demand excess attention, said Maren Davis, marketing supervisor at Highland Meadow Nursery (Molalla, Oregon). With proper care, such conifers will offer consumers beauty and longevity in a landscape, she said.
What’s more, low-spreading conifers can reduce the lawn footprint in residential gardens, she said. In industrial settings, the slower growth habit of prostrate evergreens is a plus for maintenance. One design approach would be to combine them with mixed grassy areas and groupings of taller evergreens.
In a residential setting, a good mix includes the very low and the mid-size evergreens (including broadleaf types), and then some tall narrow evergreens with various colors and textures, Davis said. With the addition of grasses and/or perennial accents, the result is a complete landscape.
For instance, Davis likes to combine one of her favorites, Icee Blue® (Juniperus horizontalis ‘Monber’), with other conifers. It hugs the ground with silvery blue foliage up to 4 inches tall and 8 feet wide. She suggested placing it with Picea pungens ‘Procumbens’ (a prostate Colorado blue spruce), Sequoiadendron giganteum ‘Pendulum’ (weeping giant sequoia), and/or the weeping and pendulous habit of P. abies ‘Pendula’ (weeping Norway spruce) to create a low tableau and a beautiful grouping of conifers.
In larger industrial plantings, she has seen P. abies ‘Pendula’ and P. omorika ‘Pendula’ (weeping Serbian spruce), which is lesser known, work as a grouping with J. horizontalis ‘Wiltonii’ (creeping juniper) wrapped around the base.
“‘Wiltonii’ is always in demand because it works everywhere,” Davis said. “I see it used in large commercial projects that use a fair number of them, and even in smaller projects.”
‘Wiltonii’ is a reliable workhorse that adapts to a range of conditions, tolerates heat, poor soils and dry growing conditions and forms a dense mat up to 8 feet wide and 4–6 inches tall. It’s also a good plant for growers. They can expect that in 18 months it will be market ready at a larger size than some of the other newer low-growing conifer varieties, Davis said.
Davis also recommended Juniperus horizontalis ‘Golden Carpet’, with a nice gold color, disease resistance and a love of full sun. It has an expected spread of 10 inches wide and a height of one foot, which makes it useful for landscapes where an annual blowing in of landscape bark or chips can be expected, Davis said.
J. chinensis ‘Daub’s Frosted’ has golden yellow new growth that retains a yellow tinge throughout the growing season and contrasts with the mature blue-green foliage; an ability to thrive on hot, dry banks in poor soil; and a flat habit, maturing at 10 inches tall by 3 feet wide.
The deep green and feathery carpet of J. communis ‘Corielagen’ is hardy down to Zone 3 and grows at a fast 6–8 inches a year, reaching 12 inches high by 10 feet wide.
Davis also recommends the Juniperus conferta (shore juniper) types, which are hardy to zone 6 and are resistant to deer, drought, erosion and air pollution. “Birds like them, and so do our native snakes,” Davis said. “They also do not have any disease issues like the horizontalis and sabinas do.”
New varieties in development
Rare Tree Nursery (Silverton, Oregon) has in development two to three dozen varieties it classifies as spreading conifers, said Sam Pratt, sales manager, but only has six to eight available at a time that are garden-worthy.
“We’re seeing a shift away from Chinese juniper that was the default in the ‘80s and ‘90s and a movement toward pines and firs and spruces that have more texture and variety than what was available a few years back,” Pratt said.
The nursery has received frequent requests for two pines in particular, especially in larger sizes.
Pinus sylvestris ‘Hillside Creeper’, a scotch pine, has been in production for a while, but customers are now noticing it for its vigor and ability to fill in spaces 10 feet wide.
P. banksiana ‘Schoodic’, a selection of jack pine, which Pratt calls a bulletproof, tough-as-nails option, is hardy to USDA Zone 2. It is very flat and resistant to vertical growth, spreading 4–6 inches per year and maturing at 4 feet.
In spruces, Pratt recommends Picea abies ‘Gold Drift’, a Norway spruce. When not staked, it forms a carpet, growing 6–9 inches per year. He also recommends P. orientalis ‘Ferny Creek Prostrate’, which is hardy to Zone 4, and tough. Its very dark, green, glossy foliage forms a more horizontal nest shape than ‘Elegans’ and covers a wider area.
Although firs are seen as high maintenance, Pratt said Abies koreana ‘Green Carpet’ is underappreciated, especially for its purple cones.
“Normally the cones are higher up in the tree for firs, but with the spreading variety you get them on the ground,” Pratt said.
For another showy display, Taxus baccata ‘Watnong Gold’ will brighten up shady areas with its spreading, somewhat bushy form, 3 by 4 feet. It sports bright gold new growth that persists in the leaf margins.
These new varieties, and even some older ones, defy the image of conifers as “prickly and boring,” Pratt said. Take junipers, for instance. Of the new varieties, Pratt has seen several that are worth getting to know.
At less than 2 inches tall, Juniperus communis ‘Greenmantle’ looks almost like moss.
“It’s very unique, and we’re trying to expedite it for sale,” he said.
If you look at J. horizontalis ‘Blue Forest’ from the top down, it looks like a small forest of vertical trees, Pratt said. The diminutive conifer reaches 18 inches in height. Renewed interest in low-growing conifers also satisfies the desire for good coverage at a reasonable cost with tough plants that will fill a space without blocking a view, he said. The challenge for growers will be fulfilling the needs of the market with plants that take longer than herbaceous plants to reach key sizes.
“A lot of the material is grafted,” Dittmar said, “and producing a #1 is not market size. Grafted material needs to get larger before it can be saleable, and a grower has to be willing to wait.”
That means customers must wait, too. But given the increasing interest in year-round plants that fill space, they’ll be ready for those conifers when they come online.