Wednesday, January 4, 2012

Evergreen needn't just mean green

Bright pink sepals glow on this abelia in winter
Photo credit; taken at Wisley Gardens by thehardyperennial,com

I’m often asked to design a low maintenance garden for clients. I consider several criteria when selecting suitable plants which I covered in my post ‘Reducing maintenance (and backache) in the garden’.

Low maintenance shouldn’t mean boring, however! An endless hedge of arborvitae or a border entirely devoted to Rhododendrons may be easy care but won’t win any design awards. Yet evergreen trees and shrubs are an important part of low maintenance design unless you are especially fond of raking up barrow loads of leaves each fall. The trick is to select several evergreen plants that change in some way during the year.

Broadleaved evergreens are those plants which keep their leaves all year such as boxwoods and holly. Many of these do provide year round interest by virtue of their flower and fruit production and so earn their place in the garden. But there are several candidates which also change color, a feature I like to look for when designing landscapes or easy care, eye catching container gardens.

Vibrant winter color on 'Gulf stream' heavenly
bamboo makes it a winner.
Photo credit; Furney's nursery
Heavenly bamboo (Nandina domestica) is perhaps the first to come to mind. These shrubs have it all; soft leaves in shades of green, chartreuse, burgundy and purple deepen to rich red in winter, especially when planted in full sun. Add to this clusters of white spring time flowers followed by bright red berries in fall, drought tolerance when established and fabulous material for cut flower arrangements and you truly have a 5 star plant. Many varieties are available including the mounding ‘Moon Bay’, richly colored and taller ‘Plum passion’ and the bolder leaved but dwarf ‘Blush pink’.



I have valued the ‘Kaleidoscope’ abelia (Abelia x grandiflora) for its bright variegated foliage for many years and it’s a popular addition to my evergreen container combinations. However I was recently given several of the non-variegated ‘Edward Goucher’ and I must say I am enjoying these in my garden even more. This large mounding shrub is deer resistant ( a HUGE plus for me) and its glossy, deep green leaves have turned a rich mahogany shade with bright red highlights .Tubular white flowers have adorned these bushes for many months, finally taking a rest when our temperatures dipped into the mid 20’s. This quiet beauty provides an understated foil for showier winter specimens such as a nearby golden ‘Skylands’ spruce. (Picea orientalis)

Leucothoe 'Scarletta' snuggles up to white violas and
 evergreen parahebe in this simple container design.
Photo credit; Whichford pottery
For bullet proof color in the shade garden I look to leucothoe (Leucothoe fontanesiana), especially ‘Scarletta' and ‘Rainbow’ whose foliage becomes increasingly red as winter progresses. These elliptical leathery leaves make good companions to the more delicate evergreen ferns such as autumn fern (Dryopteris erythrosa), soft mosses and wispy grasses such as the bronze toned leatherleaf sedge ‘Red rooster’ (Carex buchananii ‘Red rooster’). This arching shrub looks perfectly at home in the woodland garden but will cope with sun if the soil is well amended with compost to retain moisture. Leocothoe  is a favorite of mine for fall/winter container gardens and maintenance challenged gardeners! Fragrant bell shaped flowers adorn the plants in spring as a delightful bonus.

When a plant has the choice of common names ‘Pigsqeak’ or ‘Elephant ears’ you have to wonder if it wouldn’t prefer  to be known by its botanical name Bergenia! I’m not sure where the first name came from (coined in England I believe - I deny all responsibility) but at least ‘Elephant ears’ aptly describes the shape of the fleshy leaves on this easy care perennial. These thrive in partial shade with reasonable moisture and display thick spikes of white or pink flowers in spring. Equally striking however is the color  change the foliage undergoes in the colder months especially the varieties ‘Bressingham ruby’ and the more compact ‘Winter glow’. In both cases the green leaves become deep burgundy in winter. Try planting these in combination with white flowering spring bulbs such as drifts of crocus to create a vivid early season vignette. Alternatively the white variegated foliage of andromeda ‘Flaming silver’ (Pieris japonica) would provide longer term interest.

It is only since moving to the United States that I have gained a better appreciation for conifers in the garden. Long gone are the days when we were limited to choosing between a monster juniper to swallow the garden or a pine tree which towered over the house. Now we are tempted by beauties in shades of green, blue and gold from the petite to the giant. Still not enough choice for you? Well there are many fabulous conifers which even change color during the winter, some of which actually look their best in colder months!

'Winter gold' mugo pine really stands out in the
winter garden.
Photo credit; cnso.biz
The dwarf mugo pine ‘Winter gold’ (Pinus mugo) is on my ‘must find’ list and I may have to resort to e-gardening to find it! Conifer expert Adrian Bloom expounds the beauty of this in his book ‘Gardening with conifers’. The long, dark green summer needles transition to golden hues in late autumn. What a perfect contrast to black mondo grass or another great winter conifer; Siberian cypress (Microbiota  decussata). The prostrate form and lacy texture contrast well with the tufty pine but the winter color combination is exceptionally striking as the Siberian cypress turns purple-bronze just as the pine reaches its golden peak. This tough conifer just asks for full sun and good drainage. Its mature size is 12-18” wide and 10-16’ wide but can be trimmed for size.

'Forever goldie' arborvitae
shows burnt orange foliage at
this time of year.
Photo credit; Ballhort.com
Some conifers have a rather muddy winter complexion in my opinion, such as the popular Hinoki cypress (Chamaecyparis obtusa). Yet once again these can serve to highlight brighter companions such as ‘Rheingold’ arborvitae (Thuja occidentalis ‘Rheingold’) or the larger ‘Forever goldie’. Both turn a distinctive orange shade in winter, returning to summer chartreuse/ bright green.






Chamaecyparis lawsoniana ‘Blue surprise’ Port Orchard cedar (Chamaecyparis lawsoniana ‘Blue surprise’) is a favorite conifer of mine for both landscape and container design. Its bright steel blue, finely textured foliage is gorgeous enough. The tight columnar form makes it suitable for narrow spaces while its mature height of 10’ earns it a place as a vertical accent in many designs. The new 'Guardian Series' by Monrovia now offers these as grafted trees eliminating the worry of root rot which can be a problem in some areas. However this beauty has yet another attribute – it gains a delicate burgundy cast in winter. Plant this in full sun where you can enjoy it year round and you won’t be disappointed.

Many other examples of chameleon plants abound including wintercreeper (Euonymus varieties) and the Japanese plume cedar (Cryptomeria elegans). Visit your local nursery to see what is on offer or a botanical garden to see examples of successful winter vignettes.

Remember, evergreen doesn’t have to mean always green.

7 comments:

  1. Many of these plants are my favorites because they offer fall and/or winter interest. Nandina is such a stunner. I think I will add more this year. Happy new year!

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  2. The Heavenly Bamboo is aptly named, and I love the golden Arborvitae! Chameleon plants are fascinating and great fun! Thanks for sharing your wisdom about colorful "evergreens."

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  3. Two more, Microbiota decussata, a prostrate shrub, green most of the year, bronze in winter, and Chamaecyparis pisifer filifera 'Aurea' (repeat three times fast), gold most of the year, only slightly dulled in winter.

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  4. Well I"M going to get a gold mugho pine for sure..... I must admit it took me a while to really appreciate colour changes.... I guess it was my real distaste for poorly displayed boxwood that went a chlorotic looking orange in the winter. But how can you not smile at a choysia sundance, looking like the sun is out over in a corner... My latest discovery is pieris "katsura" It's just come on the availability lists locally.
    Monrovia has great stuff, unfortunately up in Canada it's costly, with patent fees, duty and taxes.
    The coolest Acer for my shade garden would be a A. japonica 'golden full moon maple" But those darn folks at Monrovia have tempted me by introducing a Acer circinatum "pacific gold" that has me drooling. Just got to wait till they aren't so costly.

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  5. this is a great post! not only is the text helpful the images really drive the point home. Nice combination.

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  6. Mark - I love that Chamaecyparis but 'Sungold' is even brighter!

    Anne-glad to have given you an excuse to go shopping!! You have one the same for e though - I need to find that Pieris 'Katsura'...
    I do have that golden full moon maple already in dappled shade and it is a highlight of the garden. I use them in container also. I have also used the 'Pacific fire' variety of Acer circinatum (vine maple) which is pretty amazing.

    Lisa - Thank you!

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  7. Hey Anne - I think I have a 'trial size' Pieris 'Katsura' in the garden from Brigg's nursery - must go and check the tag. How exciting!!!

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