Saturday, December 29, 2012


Spodiopogon sibiricus
Frost Grass, Siberian Graybeard, Silver Spike Grass

Frost Grass is an attractive clump-forming ornamental grass from Far East Asia; China, Korea, Japan and Siberia. Growing on lower mountain slopes, forest margins and roadsides it has the upright sculptural appearance of bamboo.

6” to 8” leaves taper horizontally from shoots through spring and early summer. The bushy appearance changes as light catching 12” terminal panicles emerge in mid-summer. Foliage color changes to red or burgundy in fall.

Frost grass can create large clumps 4’ high and 3-1/2’ wide, plant as a fall specimen or in massive sweeping groups. The light green foliage creates a blending background element. While the foliage remains dense to the ground and does not require a facing element, I love a rock facing or surrounding scaled boulders comparable to its native mountain slopes. Russian Cypress provides a valuable native companion. Recommended spacing between plants is between 18”-40”, it is rather slow growing and lives for more than a decade.

Well-drained, mesic soil is desired for good appearance, wet soils should be avoided. Frost grass is not drought tolerant and should be watered to root depth every few weeks. Full sun is optimal, the grass is partially shade tolerant; in hot summer climates, more shade is recommended. It is not particular about pH. This grass is tolerant of urban pollution and salts.

The panicles only look good through fall, Frost grass is often cut back before winter sets. The dried panicles are great for dried flower arrangements.

This grass is generally propagated by division. The cultivar “West Lake” was collected from China for its pinkish-red panicles. Zone 3-8.

Saturday, December 22, 2012


Russian Cypress
Microbiota decussata

This singular species was found by the Russian botanist Komarov in 1921, introduced into western gardens in 1957. Popularized in 1973 at the Chelsea Flower Show in Great Britain, it is rather uncommon.
This conifer belongs to the family Cupressaceae and is closely related to junipers (Juniperus) and true cypress (Cupressus).
Russian Cypress is a low spreading evergreen shrub 1’ to 1 ½’ high, spreading 4’ to 8’. The scale-like foliage is soft, delicate and feathery light-green in appearance. Like Eastern redcedar (Juniperus virginiana) the foliage turns purplish brown in winter. Inconspicuous woody single-seeded cones can be irregularly produced.

Russian Cypress is best suited to moist, loose, well-drained preferably acidic soils. In full sun it requires adequate moisture; it also can grow in partial to full shade. In poorly drained soils root rot can be a problem; it experiences no serious diseases or pests. Deer may browse the foliage.

Also called Siberian Cypress and Russian Arbovitae, this shrub is found in mountainous areas of eastern Siberia, in the lands of the Siberian Tiger. This shrub is often chosen as a groundcover over junipers because it is less susceptible to blight. It is tolerant of wind and salt, excellent for coastal areas and roadsides affected by winter road spray. It works well on slopes or embankments mixed with rock boulders. I have used Russian Cypress in rock delineated borders with rhododendrons, Frost Grass (Spodiopogon sibiricus), Artemisia lactifolia guizhou group a White Mugwort cultivar, Joe-Pye Weed (Eupatorum purpureum), Siberian Iris cultivars or Iris lactea.

‘Fuzz Ball' is the only cultivar and has soft, fuzzy foliage. It is more compact with somewhat rounded form. It makes an ideal conifer for the rock garden.

Russian cypress is an excellent groundcover choice for northern landscapes. USDA zone 2-7.
Tell me of your experience with this conifer shrub!

Saturday, November 24, 2012


Iris typhifolia Kitagawa
Siberian Iris have been gaining in popularity for decades. Garden Siberian Iris have been developed from two species, Iris sibirica and Iris sanguinea. A third species was known from a specimen discovered and collected in 1928.With flowers in three parts the race of garden Siberians now come from three species.

Its common name in the west is the Cattail-leaved iris, in China it is known as North Tombs Iris. Iris typhifolia is found in northeast China, Inner Mongolia and the southern border of Far East Russia. It has wide distribution along the Amur River valley.

It grows in ecological systems associated with water; wet meadows, permanent swamps, rivers, temporary streams, seasonal wet spots. These are surrounded by northern broadleaf and coniferous forests.
Iris typhifolia 'Caitlan's Smile

A delicate beauty
Iris typhifolia flourishes in continental climate extremes, winter temperatures below -20F, summer heat to 100F degrees. Rooted in glaciated soil types and watered by northern temperate rainfall cycles of seasonal spring rains followed by droughty summers.

Long inaccessible during the cold war it is now a contribution to our gardens from northern China. With the opening of trade in the early 80s seed was collected and distributed to Kew Gardens and iris experts in England. It first flowered in 1989, young plants often failed with moderate winter weather, bloom was arrested by late spring frosts. It was determined it preferred a later more northerly spring season due to its early bloom habit. Iris typhifolia blooms weeks earlier than its sister species.

In 1992 further material was distributed from plants and seeds collected by Dr. James Waddick, Powell University, Missouri and Professor Zhao Yu-tang of Northeast Normal University, China. Their collaboration resulted in the book Iris of China. Members of the American Iris Society who sponsored their expedition received seeds and propagated a wide variety of seedlings.

Leaves are narrow, upright and elegant, sometimes twisted. The stem base can be reddish, flower stems smooth and hollow, bracts mottled brown or with reddish spots. Species flowers are generally shades of violet- blue with no known color variations such as white found in its sister species. Variation is found in flower form since seed collection was done from a variety of native colonies. Bloom occurs in early spring, weeks before other Siberian iris species and cultivars.

Cultural requirements are similar to most garden Siberian iris; sunlight conditions are full sun to light shade, soil pH average to acidic and wet mesic soils. (Please review Siberian Iris culture sheet found in this blog site.) 

Propagation is by seed and division. Species plants from seed, hybrids by seed or division. Seeds which ripen from July to September will bloom in their second or third season.

Hybridizers have found that Iris typhifolia contributes early bloom, added hardiness, different foliage characteristics, repeat bloom and prominent signals. New hybrids have expanded the bloom season and added classic butterfly forms with some color variations in white and greater range in blue.

Iris typhifolia ‘Caitlin’s Smile’ is a selected species form with erect foliage and purple blue flowers. 'China Spring' is the first introduced Iris typhifolia hybrid; it’s a great harbinger of the coming flowering season. 'China White' is a typhifolia hybrid. 

Iris enthusiasts and gardeners should seek out Iris typhifolia for its novelty and as a companion plant in moist gardening conditions. Its flower form works well in natural gardens as an early spring accent with wet mesic ornamental grasses and perennials.

Seek specialty iris growers for purchase of Iris typhifolia and its hybrids. Seed can be purchased through the Species Iris Group of North America (SIGNA).

This delightful iris can add great delicate beauty to your spring garden.

China White

Sunday, November 18, 2012


Siberian Iris - my garden of the 1990s

I have grown Siberian Iris for decades, in the 90’s I really expanded my space for growing and hybridizing. In 2000 my garden collection was on tour for a Siberian and beardless species convention conducted by AIS Region 8.  The garden included guest plants from hybridizers around the country.

The 80’s and 90’s saw the maturation of flaring and flat rounded forms of Siberian flowers.  The process begun with White Swirl in 1957, flatten standards and flaring falls which fully close to a complete circle had reached fruition. The traditional butterfly forms with pendant or arched falls provide color from a distance. The modern flattened form looks best upon approach, looking down at the plant. All forms of flowers are acceptable to enthusiasts.

More tetraploid cultivars were introduced inspired by the success of Jeweled Crown (Hollingsworth ’85) which was the most popular Siberian of this time. It was soon to be superseded by another Hollingworth tetraploid Strawberry Fair.

Tetraploidy is induced by treating seed with colchicine or other mutagens; the surviving plantlets will have twice the chromosome count. Plants will have heavy substance, larger parts, robust growth and vibrant color. 

Jeweled Crown
I had bought Jeweled Crown in its year of introduction; in ‘87 it bloomed for the first time. The bud spathes are crimson and rise through the foliage as a band of color to burst into large ruffled crimson velveteen flowers. The signal is large and golden; all parts are of heavy substance. By the late ‘90s I had large clumps. The plant provides an impressive spring display, an excellent accent plant.

Sometimes Jeweled Crown blooms inside the foliage with warm spring temperatures. Another fault with this cultivar and nearly all tetraploids is the dense substance rips and tears in heavy weather. This is not the case with butterfly forms and diploids (normal 28 chromosome count) which are noted for their ability to hold themselves together in the worst spring weather. This ability is one of the many excellent traits of Siberian Iris as landscape perennials.
Harpswell Velvet

In contrast, Harpswell Velvet, another tetraploid, is dark blue with wire rim around the falls, an excellent example of form with arched falls and upright standards.


Ships Are Sailing
Ships Are Sailing is a remontant blooming Siberian Iris. Remontant bloom is a form of rebloom, rather than blooming in another season like some bearded iris, Ships Are Sailing blooms again, often weeks after finishing its first bloom season. This is a much sought after quality. Extending the bloom season is highly desirable to all perennial plant lovers. Cool soil temperatures appear to trigger this trait, induced by heavy mulch or cool weather and rains. I had a friend who had a daughter of this cultivar which had very late, late July bloom season. Unfortunately this hybrid appears to be lost.
Countess Cathleen
Ships Are Sailing won the Morgan-Wood Award in 2007, this high award is well deserved. With bi-tone blue ruffled flowers it is a heavy mid-season bloomer. It grows to three feet; it amplifies the landscape paired with Sea of Dreams and Countess Cathleen. This complementary group can act as a foundation for a spring garden event.
Sea of Dreams
 Another cultivar which can be combined in this group is Neat Trick, dark blue with white mottling throughout the standards and falls. Neat Trick is very popular, a breakthrough which unfortunately has not led to more mottled cultivars.
Neat Trick
Some connoisseurs do not appreciate multi-petaled varieties, but all types of forms are allowable. Concern surrounds the display of petals in a haphazard versus symmetrical display. Shebang hybridized by Japanese Iris growers Bauer and Coble makes a great spectacle.
Jamaican Velvet
A couple of intros in the ‘80s, Jamaican Velvet and Liberty Hills formed large clumps to be clustered in threes and fives throughout perennial beds. Liberty Hills is French Blue with triangular falls. Magenta colored Jamaican Velvet has blue accents.
Liberty Hills

Uber den Wolken is light blue, I have used this cultivar repeatedly in hybridizing, resulting in a few small flowered light blues with fabulous modern form.
Uber Den Wolken
All these cultivars are now common in the market through specialty iris growers.  I encourage gardeners to use Siberian Iris in their perennial beds. Comment to me how you use them in landscapes. I will compile my ideas into further blog postings. I also encourage readers to hybridize Siberian Iris, I plan further postings around this topic.

Tuesday, October 30, 2012


The uncommon ornamental hawthorn


Over the last two fall seasons I have been inspired by the subtle color of Thornless Cockspur Hawthorn, Crataegus crus-galli var. inermis to investigate the entire hawthorn family.



 

The Thornless Cockspur Hawthorn is a small tree 15’ to 20’. The dark green glossy foliage, borne along layered branching becomes a rounded and spreading crown.  The red haws, fruit, grow in abundant clusters accenting the yellow to brown fall foliage which drops to show a twiggy winter appearance.

The species can be either a large bush or small tree. Crataegus crus-galli  has numerous long thorns. In late spring white musky scented flowers appear in trusses of 5-30 flowers.  Native to eastern North America, it is hardy from USDA zones 4-7.

Hawthorn has been used in herbal teas, candies, jams and wine. The wood is extremely hard and creates a hot fire. In Europe thorny hawthorns have been used as pastoral hedges to confine livestock and provide windbreak.

Trees can be easily cultivated in good, well-drained soils they can tolerate periodic wet feet and need extra water in droughty conditions to prevent defoliation. Hawthorns are tough trees of great ornamental value.

Unfortunately hawthorns are susceptible to a number of pests and diseases. Cedar-hawthorn rust and apple fireblight are significant problems.  Left untreated these can damage a tree.

Folklore surrounding hawthorn is extensive, in some parts of Europe the flowers are unlucky, due to  connection with the crown of thorns worn by Jesus. In southern Europe hawthorn is known as May Flower or Mary’s Flower and therefore cherished.

There are roughly 200 species of hawthorn shrubs and trees found throughout northern temperate regions. 150 species are found in the United States, 12 are found native to Minnesota. As a boy I remember running into a thicket of Crataegus macrosperma, Eastern hawthorn, a very unpleasant prickly experience. These native trees have vast potential for breeding superior new varieties. My boyhood experience shows that a number of problems can be resolved, thorniness and suckering are two! Fruits could be improved for commercial production. Ornamental qualities of foliage, flower and fruit color beckon for attention from young horticulturalists.

Thursday, August 16, 2012

Siberian Iris Season 2012

Spring Beauty

The 2012 season began weeks ahead of the prior year. When I began growing Siberians decades ago peak season was around June 15th, the season began at the end of May. I attended my first Iris show in the mid-90s, the show was scheduled for the first weekend in June I brought a couple early bloomers and won the Siberian section with  “Heliotrope Bouquet”.

This year the first to bloom was I. typhifolia “Caitlin’s Smile”, it opened May third. By June third the season was nearly over which typically finishes around Independence Day.

Iris typhifolia was discovered in 1928, it was introduced into the US in the late 80s. Today less than a dozen selections and hybrids have been registered with the American Iris Society.      

Shakers Prayer, a near species hybrid was next to flower. It looks similar to the species I. sibirica but shows many more irridesent shades of blue. Both early blooming Sibs have the typical butterfly form cherished by many gardeners.

Shakers Prayer
My SI season lasts about six weeks. Some of my favorite new cultivars were spectacular this bloom cycle. “Fond Kiss” is white with a big pink blush emanating from the signal. The large flowers have flaring ruffled standards and recurving falls. The plant is about 36” tall. Fond Kiss won the Morgan-Wood medal in 2008, the highest award given a Siberian Iris.
Fond Kiss
There are a number of new yellows, far improved, more colorfast than Butter and Sugar, an old standard found in most nurseries. “Lady’s Chain” has medium sized flowers, a yellow bitone with light yellow standards, golden falls, open form, flaring standards and overlapping falls which comprise the modern model.   
Lady's Chain
“Dance and Sing” has upright yellow petaloid style arms, light yellow standards and dark yellow falls. A large all yellow flower. The plant is roughly 32” tall and noted as a rebloomer, not yet in my garden. “Summer Revels” is another yellow bitone which makes a marvelous clump and adds  contrast to many blue-toned SIs. I also recommend the following yellow cultivars; Just Cruising, Kiss the Girl and Lucy Locket mostly bitones or bicolors. Light yellow or white standards and yellow falls. 
White Amber
“White Amber” is a new departure adding pink over a base of yellow. The falls open pink and fade with age to yellow.




“Miss Apple” is stunning, smallish rounded flowers with violet standards and reddish falls. These contrast with large yellow signals surrounded with white.

Miss Apple
I rejoice that the Society for Siberian Iris created garden judging guidelines which allowed for all forms of SIs. Few dwarf Siberians have been registered, only a couple have been multiplied for the retail market. “Baby Sister” is available through many nurseries. It is blue, about eight to ten inches tall and blooming just above the foliage. Dwarfism is a recessive gene; many small Sibs are weak growers often with many additional poor traits.

Summerchase Advent
A few years ago I introduce “Summerchase Advent”. A dwarf daughter of Baby Sister, the plant is eight to ten inches tall. The flower is white with a green throat. Flaring flowers are large and allow viewers to look down at a mass of white. The clump shown is two years old, it is a vigorous grower. After blooming the blue green foliage is an effective groundcover, much like ornamental grass. SC Advent has been an effective parent of dwarf Siberians.

At the opposite spectrum I was impressed by a tall SI with large white flowers. I saw “Swans in Flight” in a couple gardens.
Swans In Flight
A mid- to late-season bloomer with erect blue-green foliage. Sib foliage creates more than one season of interest turning brown after frost. It adds another effect when mixed with ornamental grasses.
 
Siberian Iris are excellent landscape plants. Sibs have many desirable traits:

·       Few insect and disease problems.
·       Tolerance of many soil types and conditions.
·       Low maintenance requirements.
·       Varied foliage heights and color.
·       Growing range of flower color and form.

Clump of Swans In Flight
One trend in breeding are multi-petalled cultivars. Breeding efforts begun in Japan have inspired American hybridizers to create new varieties.
Rikugi Sakura

Imperial Opal
Some gardeners see these as novelties of passing interest. My favorite is “Tumblebug”, wine-red with yellow signals. It has roughly twelve petals. At a distance it looks like a simple rose. “Imperial Opal” is a late season bloomer with large lavender-pink flowers of twelve to twenty petals. This plant is very showy an excellent late spring accent.

These are tough, easy and reliable plants for any perennial garden. Please search out these modern hybrids through specialty iris growers. Check the American Iris Society or Society for Siberian Iris websites.
 
If you have any questions about Siberians please leave a comment or question.
 
Check out my recent post Siberian Iris 2013! Don't forget to check out my culture sheet also!





Sunday, July 29, 2012



Siberian Iris Care


Siberian Iris Culture Sheet


Sub-series Sibiricae – Throughout this culture sheet the 28-chromosome group comprising species I. sibirica, I. sanguinea, I. typhifolia, and their hybrids will be called “garden” Siberian iris.

Sub-series Chrysographes - The 40-chromosome group comprising eight species and their hybrids will be called “Sino-Siberian” iris. 

Climatic Conditions

Garden Siberians: These species and hybrids are adaptable to a wide range of climatic conditions and are very cold hardy. I. sanguinea is native to Siberia. They flourish in all temperate regions with sufficient rainfall. They are more difficult to grow in hot arid locations requiring special conditions such as semi-shade, extra mulch, and abundant water. Established clumps do not require winter protection with mulch.  USDA Zones 3-9

Sino-Siberians: Native to high altitude meadows and streams in the Himalayas. The species are not subject to either temperature extremes. Summers are cool and winters are mild with ample moisture and humidity. In northern climatic zones heavily mulch in the winter. Mulch to prevent moisture loss in hot climates. USDA Zones 4-8

Site Preparation and Soil Requirements

Both sub-series of Siberian Iris have the same site and soil requirements. These irises like full sun except in hot arid regions. They can tolerate some shade, but less than half a day of sun will be met with a reduction in bloom and vigor. They tolerate a wide range of pH, but prefer neutral too slightly acidic conditions, pH 5.5 to 6.5 is best. They can languish or dwindle in alkaline soil. They prefer rich soil with ample organic matter. Thoroughly composted manure, peat moss, and other organic materials make excellent soil amendments. They like abundant moisture and early in the season can withstand flooding for short periods of time, yet they are not water iris and a site should have adequate soil drainage.

Planting

Prepare iris for planting by cutting leaves back to 6 or 8 inches and soak the roots for several hours before planting. Remove damaged roots and rhizomes. Inspect the roots for intertwined weed or grass roots and remove them.

Planting can be as simple as making a hole wide and deep enough to receive the root system. The base of the leaf system or crown should be roughly 1” below the final level of soil. Make sure no air pockets remain around the root system. Thoroughly water the iris at the time of planting and for the first couple of months after planting, not allowing the plant to become dry. Additional culture can increase performance such as spreading roots over a mound of thoroughly composted manure in the base of the hole and applying a weak solution of root-stimulating hormone.

Traditionally early fall is the best time for planting bare root material giving roots and rhizomes chance to anchor before winter. In northern regions Spring planting can be successful. Within your garden transplanting with a root ball of soil avoids transplant shock. Spring planted Siberians may be expected to flower the following year. Fall planted iris cannot be expected to flower until the second year.

 To maintain abundant bloom and vigorous growth you can transplant Siberians every five to ten years. Divide clumps with fork or spade and remove old roots and rhizomes from the center. Transplant the outer portions as you would new plants.

 Water

All Siberian irises like abundant water during the growing season, 1” of water weekly is recommended.

Established garden Siberians can tolerate dry conditions later in the season. Some growers flood Sino-Siberians every 3 to 4 days during the growing season if conditions are dry. Do not allow newly planted stock to dry out.

Fertilizer
Siberian Irises are moderate feeders. A minimum program of balanced 10-10-10 granular fertilizer may be applied as new growth appears, just after bloom, and once in early fall. Fertilizer should not be applied to new plantings for a month. Some growers apply soluble fertilizer twice in early spring, once before bloom, after bloom, and in early fall.

Mulches

Mulching provides four advantages: Controlling weeds, conserving water in the soil, moderating soil temperatures, and winter protection. Pine needles, shredded leaves, wood chips, pine bark, straw, and peat moss are excellent choices. New plantings should be mulched the first year to moderate soil temperatures while roots and rhizomes increase. Mulching also prevents heave from winter freeze and thaw cycles. Though always beneficial, well-established plantings may only need mulching for weed control. In areas of climate extremes Sino-Siberians should be heavily mulched for moisture retention and winter protection.

Additional Culture

Flower stems and unwanted seedpods may be removed so the plant will return energy to root and rhizome growth.

Foliage should be cut and removed in the fall after turning brown. This removes sources for future pest, fungus, and disease contamination.


Copyright - W. Dougherty

LA Lilies


A New Star

LA lilies, so called because they are crosses of L. longiflorum, the Easter Lily, and Asiatic lilies were developed for the floral trade by the Dutch. They can add a “wow” factor to your garden.

These summer flowering lilies have large flowers of heavy texture. They have thick stalks which do not fall over in heavy winds. I call them Asiatic lilies on steroids! Because they have only been available for a few decades they do not have the color range of asiatic or oriental lilies. 
South Point
Orange is a common color for lilies. South Point can be a spectacle; you may want to replace your orange Asiatics with this dynamite! A mass can provide an explosion of color, huge full petals with dark stamens and spots surrounding the nectary.


The wonder of a desert sunset can be seen in your garden. Royal Sunset is a very good grower, floriferous with large flowers. This lily is a great accent with orange and yellow companions.


Royal Sunset


Suncrest is yellow with green throat and purple spots.The very large flowers are open with long petals.

Suncrest
Litouwen is a glorious pure white. As cut flowers the floral display can last weeks.



Litouwen

Brindisi



Brindisi is a large flowered pastel pink. There are many pinks created by Dutch breeders for the cut flower trade. Brinsdisi is a personal favorite.
I am confident that LA lilies can provide a significant contribution to your garden. Single plants or massed for effect, LA lilies deserve a place in your summer garden.






Wednesday, July 25, 2012

Standard Dwarf Bearded Iris


SDBs rock!


Standard Dwarf Bearded Iris are exceptional rock garden plants. I companion them with sedums for a long season of color. SDBs provide a burst of spring color and the foliage provides a vertical accent throughout the growing season. Sedum foliage can contrast with SDB flower color and carry interest past the iris season.
Sedums add contrasting foliage


One of my favorite SDBs is an older variety created by a local hybridizer. “Dress Whites” is not found in the nursery trade. I picked it out of an iris society sale decades ago and shared it with many gardening friends over the years. The complex colors work well with the fresh greens of spring. Like all SDBs it requires little care mostly transplanting every few years.   
Dress Whites

A combination of light blue, green, highlights of gold and brown. The foliage is blue-green with a white margin.
Check out your local iris society sales! 

Monday, July 23, 2012

Dwarf Siberian Iris

Little floral gems

I have grown Siberian Iris for decades; over the last ten years I have tried to breed small Siberian Iris. My goal has been to create small Sibs that fit into the same size classes as median bearded iris, between 8” to 18” tall.
Summerchase Advent
A few years ago I registered and introduced Summerchase Advent a dwarf, 8” to 10” tall. It has been a very good parent for small iris.


A nice yellow bitone

A floriferous blue

Iris Sky Blue Waters

Tall Bearded Iris - Sky Blue Waters

Have not had time to blog, life has been very full. Totally missed showing my gardening friends some of the highlights of the iris season.

My buddy Jack Worel has been hybridizing Tall Bearded Iris for decades. A few years back he gave me a  piece of a light blue he was going to discard. It had not performed well in his trials. It performed beautifully in my garden. With his permission I showed it at a local Iris show , it won Best Seedling.  I gave a piece back to Jack after it was viewed at a Tall Bearded Iris Society meeting held in Minneapolis. Everyone raved over what was then called “Bill’s Big Blue”, BBB for short.  Today the TB is registered as Sky Blue Waters.  I have been an AIS garden Judge, I understand what comprises an excellent TB iris, Sky Blue Waters has been a fabulous show iris and been magnificent in the garden.


Sky Blue Waters in Jack's garden

Tuesday, April 3, 2012


Rhododendron ledebourii

Currently flowering in my garden (March 21) are two clones of Rhododendron ledebourii also called R. dauricum  var. sempervirens. This plant is one of the parents of the popular PJM hybrids with Rhododendron carolinianum. The pink-violet flowering clone is unremarkable, its offspring are superior shrubs.  The other clone is white flowered, with green foliage, unlike its sister and daughters who have reddish foliage. This is a fine, vigorous and robust rhodie in my USDA zone 4 garden.

I ordered these plants a few years ago from the Rhododendron Species Foundation along with species and hybrids of what was formerly Ledum, Labrador Tea. 

Rhododendron ledebourii is native to Siberia and Mongolia. Found on rocky slopes, in clearings, along streams in forests and in subalpine zone. An evergreen lepidote, scaly small-leaved rhodie, I always covet more shrubs to propagate and hybridize. It deserves more attention in my region which is dominated by PJM and and the U of MN. azaleas.
R. ledebourii

Monday, February 20, 2012

Actaea (Cimicifuga)

Actaea (Cimicifuga) – more shade garden plant selections

Names, names, names; some common names are bugbane, snakeroot, cohosh or fairy candles; in order to remove confusion the group was reclassified from Cimicifuga to Genus Actaea. However named these wonderful woodland plants can add background structure, height, and colorful foliage to your shade garden. There is a great deal of nominal confusion and many plants are sold with invalid names. The first specimen I added to my garden was tagged Cimicifuga racemosa ‘Atropurpurea’. This seedling strain from Korea and Japan has also been sold as C. ramosa or C. simplex ‘Atropurpurea group’. The species is now named Actaea simplex. It is difficult to tag what you are growing!
   
I always scan native plant nurseries and the internet looking to add a species or selections to my garden.
Many people are attracted to the pricey purple–foliaged selections from Actaea simplex, I have grown Hillside Black Beauty, Black Negligee, James Compton, and Brunette. The foliage will darken as the plant matures yearly. Native to woodland margins in semi-shade, shelter from high winds which can tear the plant apart.

A. simplex 'atropurpurea' emerging



Early to emerge, the plant will build a base of foliage from which grow flower spikes of bottlebrush white or pink flowers. Blooming in fall from late August in the case of A. americana to frost, some species are heavy scented attracting bumblebees.


North American native A. americana, American or Mountain Bugbane, has large compound leaves and stalked wands of  vertical white flowers. It grows 4-6 feet tall.  It differs from A. racemosa, Black Snakeroot or Cohosh with a single wand of snaking flowers. Blake Snakeroot is heavily collected for a compound used in drugs for menopause. Actaea rubifolia, is commonly called Appalachian Bugbane, has rounded maple-leaf like foliage.

Another Asian species I have collected is A. japonica, with glossy maple-leaf foliage. Often flowers are killed by frost, it has self-sowed infrequently. It averages from two to three feet tall.


Actaea japonica

Actaea rubifolia


Bugbanes- value in the garden

¨      Very cold hardy, USDA zones 3-7
¨      Prefer semi-shade woodland setting; rich, moist soils.
¨      Not invasive
¨      Infrequent care once established
¨      Fall blooming
¨      Unique colorful foliage
¨      Foliage and erect flower spikes add structure

My collector wish list includes three Asian species: A. dahurica with branched flower stems. A. mairei, a large plant with green flower heads eight feet tall. A. purpurea, is not in cultivation, it is reported to have purple-black flowers. There is also a variegated form of A. simplex which may not be cultivated in the United States.

I do love all their natural colors and forms but, the pollen dauber in me wants to create a purple-foliaged A. japonica or A. rubifolia. Different flower colors exist, A. foetida has yellow flowers, A. purpurea, purple flowers, I would love to experiment with different color combinations.
The most important task would be to propagate all species and hybrids and make them available to collector and gardener alike.


Hillside Black Beauty 1 yr. transplant

In the proper conditions bugbanes are highly sustainable shade plants which add attractive foliage, height, color, and fall flowering for temperate gardens.