Wednesday, December 29, 2010

Champion Coastal Conifers

Winter is a great time to assess the bones of your garden. With all the deciduous plants bare and flowers removed or cut back, we can really see the structural evergreen plants.

Picea abies 'Pendula'
Evergreen plants fall mainly into two large categories: broadleaf and conifer. Technically "conifers" should indicate cone-bearing, but for our purposes we will simply consider those plants with needle-like foliage rather than leaves.

The gardener will find a wide variety of conifers available for successful landscape use on the Oregon coast. Do yourself a favor and start your search with a leisurely stroll (or hike) in one of our many public parks or open spaces, for the purpose of observation.  Many mistakes can be avoided, and great ideas discovered, when the gardener begins by observing successful plant communities. Which conifers prefer some shade? Which need shelter from wind? Which are especially resilient near the ocean, and which ones are snapped off in winter windstorms?

The primary coniferous trees on our stretch of the coast include Sitka Spruce, Shore Pine, Western Hemlock and Western Red Cedar. The spruces and pines are most tolerant of high wind, while the hemlock and cedar will thrive in shady and wetter conditions. All of these trees, in the right setting, are potentially very large (50' or more) specimens. The prudent gardener will plant and nurture them where they won't require extensive pruning to fit the space, and instead allow them to fulfill their potential.

Excellent examples of small landscape conifers can fill that next tier on the landscape hierarchy, the medium to tall shrub or small tree. Hollywood Junipers (Juniperus chinensis 'Torulosa') have become a favorite in the Lincoln City area, with high wind tolerance and a naturally "wind-sculpted" look, featuring deep green, non-prickly foliage (rare for a juniper). These fine plants also provide for wildlife, with dense clusters of juniper berries throughout fall and winter.

Picea abies 'Nidiformis' in foreground
The genus Picea (spruce) offers gardeners a vast array of landscape conifers, with some performing quite well on the coast.  Picea abies 'Nidiformis' or Bird's Nest Spruce offers a tidy, dense, dark-green foundation shrub that conforms to a roughly 3' square profile and rarely needs pruning. A focal-point can be achieved with Weeping Norway Spruce (Picea abies 'Pendula'), a medium-height (4-5') narrow shrub that gracefully drapes layers of cascading branches. It will tolerate some wind and only needs minimal pruning to keep from spreading too wide.

The coastal gardener should carefully site spruces that are adapted to inland conditions, like the Colorado Blue Spruce (Picea pungens var. glauca). Between sandy soils, persistent north wind and sparse rainfall in late summer, these alpine trees can really struggle for moisture. They should be given some shelter from summer winds and provided regular water.

Conifers for groundcovers are a popular choice, with two of the most successful coming from the genus Juniperus. The Shore Juniper, Juniperus conferta, is native to Japan but thrives here. A popular variety in our local nurseries is 'Blue Pacific.' If you want quick cover on a large slope that's exposed to ocean winds, this blue-green beauty is the ticket. Be sure to provide good drainage-- sandy soils are ideal.

A more compact groundcover juniper is Juniperus squamata 'Blue Star.' This tidy, composed juniper sports grey-blue foliage and is slower growing than Shore Juniper. Blue Star juniper is an excellent specimen groundcover for landscapes with a bit more shelter from the ocean and very good drainage.

Conifers can also be utilized for color in the landscape during what is an admittedly bleak season. A fine example of this is Cryptomeria japonica 'Elegans' or Japanese Plume Cedar. While the species tree in its native range is a towering timber tree much like our own cedars, 'Elegans' is a shrub to small tree, and on the coast it tends to grow more slowly, ranging from low shrub to 6-8' tall tree. The outstanding feature is the soft, ferny (hence the name Plume) foliage that in winter turns bronzy for nice contrast. New growth is a soft bright green, then darkens and turns with the onset of cold weather. A bonus: the needles never drop.

Another fine conifer for the role of small-colorful-shrub is Chamaecyparis pisifera 'Filifera Aurea' or Golden Threadleaf Falsecypress. This soft-textured weeping shrub (to 3-4') holds its golden foliage year-round, providing highlights in the mostly dark winter landscape and nicely contrasting against blue conifers.

A fine reference book for northwest trees including many of these conifers, is Arthur Lee Jacobsen's classic North American Landscape Trees. For specific information on landscape conifers including great photography and design guidelines, see Adrian Bloom's Gardening with Conifers.

8 comments :

  1. I moved here about a yr. ago. I have some pines that I dont have a clue what kind they are . But I am lucky to have several of the Spruce on my property. They are almost 100 yrs old and stunning. They really do well in the winds here. At first I was a bit afraid with the wild wind and big trees around. But now I feel protected and safe. I figure if they are almost 100 and still standing, I have nothing much to fear.

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  2. I couldn't have said it better, seanymph. Sitka spruce are the most wind-tolerant trees I have ever seen. In the big windstorm a few years back, most of the storm damage was on shore pines, which grow quickly and have weaker wood. Usually if a Sitka comes down, it's from man-made damage to roots (like carving out a driveway).

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  3. A lot of interesting information. thanks for the post!

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  4. Very interesting post, give new info and experience to me.

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  5. I didn't know there were such short spruces like the picea you mentioned. Great post!

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  6. Great to see more gardeners sharing their experience with and love of conifers!

    Ed-
    Conifer Lover

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  7. I live near the west coast of Portland in the United Kingdom, and my colorado spruces exhibit variability in their tolerance to high sea salt winds. Picea pungens 'Globosa', 'Fat Albert', Erich Frahm' and 'Glauca Pendula' are very tolerant and unaffected by severe winds, but 'Hoopsii' and 'Edith' have suffered quite considerably.
    I have a very successful species Abies concolor (Colorado White Fir) plus the cultivar 'Blue Cloak' both doing very well, also Abies procera 'Glauca' , and 'Blaue Hexe' do well even in the screaming gales.
    Other extremely tough plants doing very well with the ocean storms are : Pinus leucodermis 'Satellite', Picea sitchensis 'Papoose', Pinus sylvestris 'Chantry Blue', Pinus mugo 'Wintergold', Pinus mugo 'Carstens' Sciadopytis verticillata (surprisingly!), Cedrus Atlantica glauca, Pinus jeffreyi 'Joppi', Pinus flexilis 'Vanderwolf' (very minor tip burn, hardly noticeable), Pinus thundergii 'Thunderhead', all Chameacyparis obtusas, Chamaecyparis pisifera 'Filifera Aurea', Chamaecyparis lawsoniana 'Lane' (minor tip browning on windward side), Cupressus arizonica 'Blue Ice', all Cryptomerias, all Junipers and all Thujas (though some bronzing of the latter in winter winds).
    One to certainly avoid, is Pinus wallichiana, unless you have a fairly sheltered spot.

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  8. Very informative comments Paul, we are all enriched by others' experience as gardeners! What direction is the prevailing summer wind for you? We have strong drying winds from the north in summer which is often more damaging than the wet stormy SW winds of winter.

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