Standing up for conifers

These evergreen stars provide customers with year-round color in a variety of shapes, settings and situations

By Lisa Albert

Conifers, it seems, are frequent recipients of the Rodney Dangerfield treatment: They “don’t get no respect.”

“People see past conifers at nurseries. They don’t appreciate them,” said Kevin Borts, manager of Bizon Nursery in Hubbard, Ore.. “It takes effort to get people excited about conifers. They are hard to sell even when they are unique.”

Greg Pilcher of Iseli Nursery in Boring, Ore., agreed.

“We have a real challenge,” he said. “In the marketplace, there are tens of thousands of perennials, trees, shrubs and annuals compared to hundreds of conifers. We are competing against, as much as I hate to say it, beautiful flowers. As conifer fans, we believe others should grow conifers in their gardens.”

And not just as foundation plants but as star players and companion plants in the garden.

Given their many attributes, it is hard to fathom why conifers should be a hard sell. Thoughtful selection, siting, and planting of conifers results in plants that require minimal care -- a plus for today’s busy homeowners -- while providing a constant garden presence.

And with the ever-increasing advent of dwarf, miniature, and narrowly columnar selections on the market, there are conifer options for even the smallest gardens.

Today’s choices are the result of eight to ten years’ effort, on average, from liner to finished product. Healthy doses of clear crystal-ball forecasting also plays a part; conifer growers aren’t able to make course corrections and adapt to changes in trends quickly.

Success comes for those who make accurate predictions. Pilcher believes that was the case with Jean (pronounced “John”) Iseli, the late founder of Iseli Nursery.

“Jean Iseli was a visionary,” Pilcher said. “He believed people would like dwarf conifers, so he committed the nursery to that path, releasing into commercial production plants he had developed 20 years earlier.”

Iseli’s death in 1985 came a few years before his vision was fully realized and about ten years before the advent of Iseli’s Fanciful Gardens, a line of miniature and dwarf conifers that are marketed to the patio gardener.

Iseli’s passion for plants, and especially for conifers, is a trait shared among conifer growers and enthusiasts. Without them, we wouldn’t have such gems as Picea pungens ‘Bizon Blue’ (Bizon Nursery), Taxodium distichum ‘Cascade Falls’ (Stanley & Sons), and Thuja plicata ‘Whipcord’ (Iseli Nursery).

To market, to market

Conifers may represent only a small percentage of plants offered at garden centers, but growers are doing all they can to make a big impact with tantalizing choices for the consumer.

Roughly 80 percent of Bizon Nursery’s 300 plus acres is dedicated to conifers, both can- and field-grown specimens. Row upon row of conifers showcase the wealth of interest conifers offer. Silvery-blue Picea pungens ‘Bizon Blue’ shimmers not far from the bright creamy gold tips of Cryptomeria japonica ‘Sekkan Sugi’.

Chamaecyparis nootkatensis ‘Green Arrow’ lives up to its name, an exclamation of downward sweeping foliage pointed skyward. The pale chartreuse needles of Pinus densiflora ’Aurea’ don a bright gold winter coat, intensifying as the weather grows colder.

Field-grown plants are dug in all months except May and June; Bizon irrigates the fields in July and August to extend the digging season. Some are planted into patio boxes (18-inch wooden boxes) and grown for another year, ensuring survivability.

Container plants have two advantages over field-grown: they can be shipped year-round and trucks can hold a larger volume of canned plants.

Larry Stanley, president of Stanley & Sons Nursery in Boring, Ore. and past president of the American Conifer Society, grows 3,000 different kinds of conifers in cans at the 10-acre nursery. Together, they represent some 80 percent of the nursery’s business.

Among these are approximately 100 varieties of Southern Hemisphere plants, some of which he offers for sale. Among his private greenhouse collection are several unique conifers that will be exhibited in a May 2008 Zoo exhibit about dinosaurs: Lepitothamnus laxifolius, Araucaria heterophylla, and Wollemi pine (Wollemia nobilis), one of the oldest and rarest trees, presumed extinct until recently discovered in Australia.

Stanley offers conifers in 4-inch to 10-gallon containers. His Dwarf and Miniature Conifer 4-inch pot line can be shipped all over the country, including overnight shipping, 15 plants to a box.

Iseli Nursery concentrates on cutting-grown and grafted conifers, preferring the uniformity they offer over the variability of seed grown plants. Their line of cutting-grown mugo pines includes the diminutive Pinus mugo ‘Teeny’ (1 inch per year) and ‘Slowmound’ (less than 3 inches per year), and dwarf and intermediate-sized choices, such as ‘White Bud’ (3 to 5 inches per year) and ‘Big Tuna’ (5 to 8 inches per year), respectively.

Growers would rather produce plants as cuttings grown on their own roots – it’s less expensive. However, "It’s not predictable,” Pilcher said. “We can have anywhere from 1 to 90 percent of plants succeed with cuttings. When we can’t predictably grow cuttings – when they won’t root – we graft."

Grafting promotes better performance and durability, but it doesn’t necessary guarantee 100 percent success that all will survive to be viable plants. Some, such as Japanese umbrella pine (Sciadopitys verticillata) are not only difficult to propagate but don’t take well to grafting.

The search for the next hot ticket item brings another set of challenges, especially when the “it” plant requires importation.

“Not everything can be brought over, or it gets hung up at U.S. Department of Agriculture Customs Center,” Stanley said. “Plants need Phytosanitary stickers but even then, you can have problems. I’ve experienced more problems since 9/11. I attribute 20 percent of my losses to Homeland Security issues.”

Rooting for success

Around 1920, Phytophthera lateralis, a root rot fungus, invaded Seattle nurseries, quickly spreading throughout Pacific Northwest nurseries. By 1950, it had spread into the native forests of southwestern Oregon. It spelled doom for the native Port Orford cedar (Chamaecyparis lawsoniana) and its named forms, signaling economic losses for forestry and horticultural industries.

In the mid-1980s, hope glimmered on the horizon with the discovery of a rot-resistant Chamaecyparis lawsoniana at Oregon State University. The sole survivor of several thousand seedlings exposed to Phytophthera lateralis, CF1 (Cold Frame 1, the parent plant’s location at OSU) has become the standard for forest breeding. Research continues as scientists seek additional rot-resistant seedlings to promote diversity in the forests.

Diversity isn’t quite as critical for the horticultural industry. “One rot resistant strain means that Chamaecyparis lawsoniana and more than 200 named varieties can be introduced back into the market,” said Everett Hansen, professor, OSU Department of Botany and Plant Pathology in Corvallis, Ore. “We continue to conduct more studies. We’ve found more than 200 cedar trees that have some form of resistance. However, CF1 stands up very, very well. It’s been exposed many times and has proven very resistant. We can kill it but we’ve got to work at it.”

Four years ago, Monrovia Nursery received an early release of seven different clones from OSU, according to Ron Kinney, conifer grower at Monrovia’s Dayton location. Inoculation with Phytophthera lateralis resulted in a strain deemed most resistant to the fungal disease. Monrovia plans a soft release of Chamaecyparis lawsoniana ‘Silberstar’ grafted onto rot-resistant rootstock in 2008, primarily to independent retailers in the Pacific Northwest.

“We expect to have more varieties available by 2010,” Kinney said.

Although OSU hasn’t widely promoted the news, CF1 cuttings are now available to growers. Bizon Nursery and Stanley and Sons will offer named forms of Chamaecyprais lawsoniana grafted to rot-resistant rootstock in 2008. An additional advantage, according to Borts, is that the rootstock and graft caliper up at the same rate, evading the ugly, bulbous look some grafted plants present.

Beyond the hedge

New lines of conifers, even rot-resistant forms, are useless unless consumers are educated about their uses in the landscape.

“Training the retail staff is key,” said Greg Anderson, nursery manager at Bizon. “We need them to be excited about conifers. They should look for new uses, such as conifers for rooftop gardens – the Chicago market is big on this – so that they can overcome the ‘I don’t know if I can sell it’ (concern).”

Additionally, it is suggested that retailers offer monthly or seasonal specials to draw customers in, especially in winter when conifers offer exceptional seasonal interest.

“People don’t know what to do with conifers,“ Stanley said. He suggested that home gardeners would benefit “if we figure out a planting plan for them -- perhaps a 10-page booklet with pictures à la a recipe book.”

“Put in shapes and colors, give them a list of mix and match plants and let people pick and choose,” he said.

Information should include growth rate and tips regarding proportionality to avoid having today’s similarly sized 4-inch potted plants become tomorrow’s exaggerated Mutt and Jeff planting.

Pilcher refers to Iseli’s impressive display garden as “servings suggestions.” “We could have 500 acres (of display gardens) and still not show all the possibilities,” he said.

He encouraged people to keep their eyes open and see how others use conifers. “When people see (conifers) used well, they gain confidence and are more willing to purchase and use them in their own gardens,” he said.

Pilcher praised the unselfish efforts of members of the American Conifer Society, Western Chapter, for their part in creating the Conifer Garden at The Oregon Garden. It holds an amazing collection of conifers, including one of the largest collections of dwarf and miniature conifers in the United States.

On a smaller scale, display beds at garden centers will inspire customers to see conifers as something other than hedge plants.

As for the ubiquitous hedge, Pilcher encouraged rethinking hedges to choose plants best suited for the purpose.

Is it privacy they seek or do they desire to soften a physical barrier, such as a chain link fence or a wall? Do they wish to create a border barrier or a living mimic of a fence? Instead of a row of plants, Pilcher suggested recommending that homeowners “remove a little more lawn and stagger the plants. You gain depth to the border, privacy, more visual interest than a row of green, and increased diversity (which makes it) healthier.”

Narrow, upright conifers suitable for hedges include Picea omorika ‘Pendula Bruns’, Picea abies ‘Cupressina’, Pinus leocodermis ‘Satellit’, and Pinus nigra ‘Arnold Sentinel’. Anderson recommended Cryptomeria japonica ‘Black Dragon’ as a great choice for a six to seven feet hedge. “Instead of annual pruning, why not grow something that will only grow to that height?”

When conifers aren’t moving, Anderson likes to reinvent them. Bizon offers Juniperus horizontalis ‘Blue Rug’ and ‘Wiltonii’, groundcover junipers, as staked plants, similar to Cedrus atlantica ‘Glauca Pendula’.

Dwarf and miniature conifers, marketed for small landscapes and patio gardeners, fill another gardening niche. As Pilcher pointed out, “You love plants but you can’t grow more space so it seems natural to move to miniature plants.”

Containers and troughs – both functioning as portable gardens - allow gardeners to grow dwarf and miniature plants, including marginally hardy selections. They can be easily moved into the garage or greenhouse during the coldest weather.

Lastly, one should remember that “gardeners like to push the limits,” Pilcher said. While it is important to provide the bread and butter plants, it is the ornamental plants that will get customers excited.

Lisa Albert can be reached at lja.garden@ verizon.net.

Digger magazine is produced by the Oregon Association of Nurseries Publications Department. publications@oan.org