Rich's Foxwillow Pines Nursery, Inc

Rich's Foxwillow Pines Nursery, Inc


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Conifers for All Seasons

Nursery News
September 1999

By Rich and Susan Eyre

Landscaping is a great way for landscape architects and designers to express themselves in an artistic manner and present their art to the world around them. Garden conifers can be considered the bones or skeleton of the garden and can provide high drama for all seasons of the year. Garden conifers offer landscape professionals and gardeners a diverse palette of various forms, colors and textures. These attributes enable the designer to create a garden rather than just a landscape.

Knowledge of growth rates helps in the proper selection and citing of the plant. Problems occur when fast-growing trees are planted too close to buildings and to each other. By using slower growing plants, one can cut the growth rate in half and double the life of the planting before the plants outgrow the space available.

The American Conifer Society has changed emphasis from ‘dwarf conifer’ to ‘garden conifer’ because the word ‘dwarf’ is a relative term with a variety of interpretation. Therefore, ACS has adopted the following four size categories for garden conifers. *

Category Growth per Yr. Size at 10-15 years
Miniature <3" 2-3'
Dwarf 3-6" 3-6'
Intermediate 6-12" 6-15'
Large 12"+ 15'+

*Size may vary due to cultural, climatic and regional factors. Note size of internodes to determine growth rate. Miniature and dwarf garden conifers are ideal as foundation plants. Intermediate and large sizes would require more space in the landscape.

Many garden conifers display a rainbow of colors in shades of green, yellow, orange, blue, lavender and purple. Good yellow cultivars can add color to a garden. The thread leaf Falsecypress Chamaecyparis pisifera ‘Golden Mop,’ ‘Filifera Aurea Nana,’ ‘Lemon Thread’ and ‘Sungold’ add a gold or yellow accent plus interesting texture.

Picea glauca ‘Rainbow’s End’ pushes green foliage in the spring, then pushes yellow midsummer. Tsuga canadensis ‘Golden Splendor’ is a showy Canadian hemlock. For inexpensive pyramidal habits, Thuja occidentalis ‘Sunkist’ and ‘Yellow Ribbon’ are good performers.

For a more diminutive vertical accent, Juniperus communis ‘Gold Cone’ is excellent. Juniperus horizontalis ‘Mother Lode P.P. #5948’ and Juniperus x media ‘Daub’s Frosted’ make good ground covers. Try Juniperus chinensis ‘Saybrook Gold P.P. #5014’ for a low compact spreader or semi dwarf mounding Pinus mugo ‘Aurea’ for showy foundation plants.

Favorite large growing blue cultivars include steel blue Picea pungens ‘Hoopsii,’ ‘Montgomery,’ ‘Thomsen,’ ‘Glauca Globosa’ or ‘Glauca Pendula.’ For silver-blue colors Abies concolor ‘Candicans,’ Abies lasiocarpa var. arizonica and Abies lasiocarpa ‘Glauca Compacta’ are ideal for outstanding and texture with soft fir needles. Scots pines Pinus sylvestris ‘Watereri,’ and ‘Glauca Nana’ are blue-green in color and they develop superior orange bark. For a blue, slow growing miniature juniper, Juniperus squamata ‘Blue Star’ on high standard is recommended.

Some conifers have bicolor, needles of stripes, spots or patches. Bicolor-needled trees offer high interest and often tie various colors together. Picea omorika ‘Nana,’ ‘Pendula’ or ‘Expansa’ and Picea bicolor ‘Howell’s Dwarf’ highlight green topsides and blue undersides of the needles. Green and yellow variegation are found on Pinus densiflora ‘Oculus-draconis.’ A variegated thread leaf Falsecypress with green and creamy-yellow foliage is Chamaecyparis pisifera ‘Filifera Aureovariegata.’ A German plantsman who irradiated the seed of Korean fir and the result was Abies koreana ‘Silberlocke’ which displays recurved needles showing the white undersides on curled foliage.

Many conifers go through seasonal changes and provide interest in the winter landscape. There is a group of conifers that highlight its yellow color in the winter and fade to green in the summer: Pinus sylvestris ‘Aurea,’ Pinus virginiana ‘Wates Golden,’ Pinus strobus ‘Hillside Gold.’ Picea pungens ‘Walnut Glen’ pushes neon yellow foliage in the spring, which is quite showy. For purple hues look for Chamaecyparis thyoides ‘Heatherbun’ during winter months. New growth on conifers is usually a lighter shade of green, but it can emerge as a bright yellow or red. Picea abies ‘Crusita’ and ‘Rubra Spicata’ emerge blood red in the spring, but fade to normal green with warmer temperatures. Picea abies ‘Argenteospicata,’ and Tsuga canadensis ‘New Gold’ emerge yellow in spring then change to green. White tips are a show in mid-summer on Tsuga canadensis ‘Gentsch White,’ ‘Labar’s Whitetip’ and ‘Summer Snow.’ These are fabulous accents to a shade garden.

On other conifers, the cones and seed bearing fruits are brightly colored and decorative during certain seasons of the year. Picea abies ‘Acrocona’ is a compact; slow-growing Norway spruce that produces purple-red spring cones on branch tips. Abies concolor ‘Candicans’ is a narrow, upright fir with long silver-blue needles and upright blue/purple spring cones. Many Pinus parviflora cultivars are early cone bearers so even small trees usually show off their cones. Most Abies fir trees have highly attractive inflorescence and cone development in spring.

The garden conifers provide a wide range of forms to add to the landscape. Fastigate or columnar trees add height to a garden but leave a narrow footprint in the landscape. Picea pungens ‘Fastigiata,’ Picea abies ‘Cupressina’ and Pinus strobus ‘Fastigiata’ are selections hardy to Zone 3 and like full sun. Other upright, narrow forms of conifers include: Pseudotsuga menziesii ‘Fastigiata,’ Pinus sylvestris ‘Fastigiata,’ ‘Spaans Fastigate,’ ‘Sentinel,’ ‘Bona,’ Thuja occidentalis ‘DeGroot’s Spire,’ ‘Emerald,’ Picea abies ‘Hillside Upright,’ ‘Berry Garden Fast,’ Juniperus communis ‘Gold Cone,’ ‘Suecia Nana,’ ‘Pencil Point,’ ‘Compressa,’ Picea glauca ‘Pendula’ and Pinus cembra ‘Glauca.’ Picea omorika ‘Pendula’ remains narrow with branch tips pointing up with blue undersides.

Garden conifers are ideal as foundation plants because they are low maintenance and highly ornamental. Once established, these forms do not need pruning or fertilizing. Good pyramidal forms are blue Picea pungens ‘Montgomery’ green Picea abies ‘Clanbrassiliana Stricta’ or ‘Asselyn Compacta.’ Recommended low green spreaders are Picea abies ‘Pumila,’ ‘Repens’ or ‘Elegans.’ Slow-growing globose conifers include Pinus strobus ‘Blue Shag,’ ‘Horsford’ or ‘Nana.’ A good mounding dwarf conifer is Pinus nigra ‘Hornibrook’ with outstanding white buds. Picea abies ‘Mucronata’ feature big brown buds at controlled rate of growth. Dwarf Pinus mugo ‘Teeny,’ ‘Valley Cushion’ or ‘Slowmound’ may grow 1-3 inches or less per year during the first 10 years of life.

Where high drama is required in the garden consider pendulous or weeping trees. Any weeping tree will attain the height you want by staking. After the desired height is reached, all growth is usually downward. A pendulous tree that is never staked becomes a groundcover. These include Picea abies ‘Pendula,’ Chamaecyparis nootkatensis ‘Glauca Pendula’ or ‘Green Arrow’ (narrow form), Pinus sylvestris ‘Mitsch Weeping,’ or prostrate forms Pinus sylvestris ‘Albyn’ and ‘Hillside Creeper’ are seen even more extreme if there is a slope or fall in the garden. For shadier sites Pseudotsuga menziesii ‘Graceful Grace’ and Tsuga canadensis ‘Pendula’ are outstanding.

Before planting, analysis of the site is essential. One needs to determine the exposure requirements, soil types and drainage situations so plant selections are appropriate. Most conifers thrive in well-drained sandy-clay loam soil in full sun. Sadly, many professionals try to landscape strip mine like soils found in new subdivisions where all good topsoil was removed and poor subsoil remains. Good drainage is essential to guarantee the success of most plantings. Larix, Taxodium or Metasequoia deciduous conifers, can take wet soil areas the best. Test soil drainage by digging a hole 2 feet deep. Fill the hole with water, let it drain and fill again. If the hole does not drain in two hours, the soil is limited for conifers. In heavy clay, raise the root ball half out of the clay layer and replace soil with sand or pea gravel so water and rootlets have an easy path to move.

Challenge yourself to learn more about conifers that are garden makers. Design landscapes with great plant material and plant in an artistic manner. Learn the value of dwarf plant material so plant size will remain scale with its surroundings without control. Be a professional that loves plants and your work will be truly appreciated. Promise to make the plants and your customers happy and you will be rewarded for your efforts.