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Allan designs and plants flowering gardens in Montreal, Zone 5 [USDA Zone 4] .

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Entries in garden design (142)


Two Full Disclosures About my Favorite Plant, Rainbow Knock Out Rose

July is a brutal month for most perennials. It is also the time when even the most floriferous of roses will take a break from putting on impressive displays. My favorite rose, Rainbow Knock Out, is not spared this intermission; during this past July, I was finally able to witness how it coped with the temporary transformation brought on by the heat of summer. It was not a pretty sight and my observations might help to explain why this otherwise amazing rose bush is not popular anymore with garden center owners.  

The first image demonstrates how beautiful this bush can be in the temperate weather of early summer.

The second image shows what it looks like in July. By then, the vivid coral blooms fade to white and the shimmering gold centers turn brown. My rose bush maintained this less-than attractive, white and brown appearance during the entire month of July and began to revert back to its coral glory only in August.

One may correctly presume that a prospective consumer, browsing through a nursery in July, might not be drawn to a plant putting on such a faded display. The “shelf-space” occupied by any plant is critical to encouraging customers to shop and this rose cannot “pull its own weight” when it looks so tepid. If I were a nursery owner, I, too, would be eager to replace this rose with a more attractive-looking plant.

So, what does this mean for the gardener who adores this rose, in spite of its shortcomings? Rainbow Knock Out will work just fine when it is planted among, and surrounded by, colorful July-blooming plants. Its faded appearance might be mistaken for an anonymous white perennial inserted into a garden composition; it will hardly be noticed. Conversely, do not plant this rose all by itself, as a specimen, because that is when its shortcomings become blatant.

This is the third time that I post about Rainbow Knock Out Rose. Some readers might erroneously believe that I have a vested interest in the marketing of this plant. Therefore, in full disclosure, I report that, because I live in Canada, I have no opportunity to either receive any freebies from American growers [who ship awesome plants across the border to my suppliers], nor am I able to enjoy the company of their public relations representatives at garden writers’ conventions. Since blogging is a labor of love, I cannot justify the expenses associated with attending these events. I pay for my own plants and write about them whenever they enchant or inspire me.

P.S. Since I first wrote this post, Eileen, who garden blogs at Gatsby's Gardens has reported on her site that her Rainbow plant grows rather large and that, after the first bloom, she has contained its volume by shearing it down a size or two without affecting its floriferousnes.


Hemerocallis Flava: an Origami-like Perennial

Was that a giant yellow humming bird growing in my garden bed? No, It was a single bloom of Hemerocallis Flava, atop a day lily clump that I propagated the year before. The original plant, an exquisite lemon-yellow flower of unusual form, appeared bird-like from a distance. I was so smitten with its origami likeness that I decided to repeat plant another two fans of this variety in the flower bed.

The lone bloom, that appeared earlier than flowers on its two sister plants, loomed over the garden at just under four feet, even though the plant tag stated that it would reach only 32 inches in height. A few days later, the buds on the other clumps flowered, creating a tall, rhythmic repetition of yellow. With so many scapes blooming at the same time, the outline of the humming bird disappeared. Now the clusters of blooms reminded me of Bird of Paradise flowers, but in lemon-yellow rather than orange-purple.

The arrival of these yellow bird-like blooms could not have come at a more welcome time. By now, most of the late spring and early summer perennials have completed their flowering cycle, while mid to late summer plants are not quite ready to open. After all, this is Zone 4 where everything blooms later. The only companion plants flowering in tandem were shorter yellow cultivars of Hemerocallis Stella Supreme and Happy Returns. As I had ensured to have at least three each of these yellow varieties growing in the garden, the differences in the heights of all three cultivars, combined with their multiple numbers, created an impressive, recurring lemon - yellow day lily theme in the flower bed.

Also known as Hemerocallis lilioasphodelus,  the three characteristics that set Flava apart from most other day lilies are:-  the bird-like form of its flowers [noticeable only when a single bud is in bloom], its height - it towers majestically over other plants, and the powerful projection of its color. Although it is known to be fragrant, I have not yet experienced its aroma.


A Perennial Garden Will Always be a Work in Progress

When designing a perennial garden, one cannot predict with certainty how it will grow during the following season. Sun, rain, temperature, soil conditions, location, borrowed views, and a plant’s naturally - determined personality will interfere even with the most experienced gardener’s vision. Editing a flowerbed, in seasons to come, is an integral part of the design process.

The photo above demonstrates a late May-early June combination from this season that was planted last year. While it creates a satisfying visual composition, it is not growing as spectacularly as envisioned in the original plan on paper. From left to right, one can see Salvia Caradonna, Rainbow Knock Out Rose, Itoh Peony Bartzella and Iris sibirica Caesar’s Brother. A vivid pink Silene Rolly’s Choice grows in the background but it is unintentional to the composition.

For better results, the rose ought to have had more blooms on it; the purple siberian iris ought to have been growing behind the yellow Itoh peony for a more vibrant color effect and the purple-blue Salvia ought to have been closer to the rose. Except for moving the iris, the other “ought tos” are not realistic options in the narrow flowerbed that flanks a walkway. In fact, Salvia Caradonna is such an impressive perennial that by the beginning of July, it became necessary to move it to another spot in the bed where it could flourish without overpowering the garden. Furthermore, in USDA Zone 4, the rose will only pump out more blooms in early July.

Since shooting this photo, the taller purple irises were lifted and placed behind the shorter yellow peony. The intention is to create a more dramatic composition. Perhaps in their new location, the irises will contribute visual excitement when they bloom in tandem with the coral roses.

My only regret in posting this photo is that Itoh Peony Bartzella is not a friend of the camera. The bright lemon yellow saturation of its petals is so intense that light bounces off the flower, even on an overcast day. It is quite a challenge for this neophyte photographer to capture a satisfying image of this very unusual and dramatic plant.

Even with the generous advice of skilled photographers, at this time of year, garden projects leave so little time to learn how to use the camera properly. I am sure that one can control for this bleaching-out effect if one takes time to read the owner’s manual provided with the camera. With only modest results, I have relied upon the editing feature of Zoombrowser to improve the appearance of the yellow petals. My consolation is that instead of mastering my Canon Power Shot, I gave homeowners the garden of their dreams.


Geranium Psilostemon, the Species, is a Traffic Stopping, Weed-Smothering Perennial

The exotic-looking Geranium psilostemon first attracted my attention when I saw it, years ago, used repeatedly in the photo illustrations of Tony Lord’s book, Best Borders. Its flower, a bold shade of fuchsia pink, with a riveting black center eye, was staged in several eye-catching perennial combinations. Those images became an inspiration to hunt for what became an elusive perennial, because no nursery in my area had ever heard of it.

Thinking back to my college years when information came only from print sources, I began to search for it in gardening catalogues, a process that took several years. From those publications, I learned that the most interesting perennials were also the least known and rarely used. Upscale mail order houses, catering to discriminating gardeners, defined themselves by offering plants that were out of the ordinary. It was among the glossy pages of a lushly illustrated catalogue, that I found my special Geranium  priced to reflect the luxuriousness of the publication. By the time I located the supplier, acquiring the plant had become such an obsession that its high cost was not a deterrent.

After recklessly purchasing this outrageously priced perennial, and finally adding it to my flowerbed,  I noticed that the sharp black center eye, so prominent in print, was slightly less powerful in a real and unstaged setting; I cannot reproduce that intense blackness with my digital camera. Another surprise was the realization that it is a monstrous, sprawling, climber and groundcover. Weeds cannot survive in its dense, smothering path. No wonder no nursery sold it. Urban gardeners cannot consider it unless they mentally prepare themselves and physically arrange the garden so that the plant is free to consume the entire flowerbed.

As one can see in the long view above, my psilostemon, placed at the back of the border as a weed suppressant, has climbed up a four-foot fence and spread across a flowerbed six feet deep. Moreover, did I mention that this is the sixth generation of the original that I once planted? The polite aggressiveness of this perennial [it maintains a clump-like composure at its base], allowed me to lift and transplant it many times until I found an appropriate spot for it to perform. In addition, with every transplanting, a few small clumps would fall away from the mother plant but, other than my own flowerbeds, I could not find a home for them. No gardener that I knew could handle such a formidable plant.

About 15 years after acquiring this gentle giant, several local nurseries introduced a variety of the species called Patricia. The new G. psilostemon, has the same intense pink color and black center. However, the breeders were unable to eliminate the sprawl because Patricia’s messiness and spread is only 50% less than the species. That is still too much for the urban gardener.

Although, I planted a few Patricias in clients' flowerbeds, within a year I was asked to remove them. No homeowner was able to deal with the overpowering presence of this dramatic Geranium. In my own garden, I continue to derive pleasure from the original, awesome species. In spite of its chaotic personality, the intense color makes me happy, [especially when combined with blues or lemon yellows], and its long blooming period is a delight.


Delicious Purpleicious 

A new variety of Veronica began to bloom in my garden during the third week of June. It started out as a one gallon potted perennial that I received in a shipment from my supplier last season. It was not on my original shopping list. However, the freight charges were so high for the inventory needed, that I decided to increase the size of my order to amortize delivery cost.

By paging through the supplier’s catalogue, I was able to identify plants that appeared to have potential in designing flower gardens. As usual, I looked for height, color saturation, or prolonged bloom period. Finding a perennial with all three attributes would have been a pleasant surprise.

That season, I had become sensitive to purple when I contracted to design a flower garden for a client who loves any shade or tone in that family. Veronica Purpleicious, a new introduction, piqued my interest for its color, a vivid purple-mauve, and its declared bloom period, June to August. Some sellers say it will bloom until September. I suppose that applies to those who garden in warmer climates. to most perennials delivered directly from growers and nurseries, Purpleicious had been pumped with plant food to ensure impressive flowering. I did not pay attention to that attribute. Experience had taught me that plant steroids, as I call them, enhance both the height and volume of a newly delivered flowering perennial to an extent that the gardener might be disappointed the following season, when the plant reverts to its genetically predetermined performance level.

That is why I am pleased that Purpleicious is as spectacular in year two as it was when it first arrived. The greatest surprise is not that it repeats last season’s stellar performance, but that it has already doubled in volume in a very dignified manner. Some perennials become problematic when they begin to sprawl or invade. However, regal color, neat mound, and disciplined upright posture of flowering spikes make this plant’s exponential growth welcome. supplier’s catalogue informed that this plant will spread to a width of only 18 inches. Now, that’s what I call a neat plant!  I suspect that mine has already reached that potential and I am pleased. In rounded volume of its clump and plush textural quality of floral spikes, this perennial adds substantial architectural presence to the flowerbed. The intenseness of its unique medium-light purple is also welcome as it enhances and complements the traditional colors that define English-inspired gardens.

Veronica Purpleicious may reach 2 feet in height depending on growing conditions. No matter!  What it lacks in stature it compensates for in saturation, texture, volume, and overall presence. The best news to garden designers is that growers declare it will bloom for most of the summer. However, that fact still requires corroboration. If it lives up to that promise, attractive flowerbeds couldn’t get better than that! Following that, if long-term sustainability in the garden can be determined, this plant will go from exciting to spectacular.