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

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Entries in long blooming perennials (1)


Thalictrum delavayi "Splendide"

This past season, a variety of Thalictrum, that was new to my garden, gave me such great pleasure that I am eager and pleased to share that experience. Every year, a local nursery promotes one of several Thalictrum varieties. Since imitation is the finest form of flattery, each spring, I too will plant the featured perennial both in my own flowerbeds and in the gardens I design. Last year, I worked with Thalictrum "Hewitt’s Double". This year, the choice has been "Splendide".

The breeder was being kind when he named this variety. Splendid is an adjective that is so overworked on our hyperbolic, commercial, world that the name didn’t give me a hint of what to expect. To say that I am ecstatic about its performance would be to understate my glee. This perennial scintillated as it bloomed magnificently in my garden, up until the last week of September. Then, by mid October, when the older, taller stems lost their flowers, the shorter, newer ones at the base of the plant,  continued to bloom on for another few days. This is one of the best gift plants for a USDA Zone 4 gardener; it is full of so many surprises.

Of course, my jubilation at the continuous blooming is somewhat tempered because this is the first season that the plant has been growing in my garden. Who knows what the grower fed it at the outset, to make it appear so impressive or to flower for so long? Now, I must wait until next season to determine its realistic bloom time. But the pleasure of this plant is more than just its lengthy flowering period. This perennial introduces a novel shade of pink to the garden, an unusual billowy shape, exquisitely fine floral texture, and an almost humorous upside-down verticality that some fastidious gardeners might consider to be a flaw.

As we all know, nothing in the world is perfect and even the best of anything has its down side. One flaw - and only a garden blogger will care - is that this plant is camera-shy;  I had to resort to posting professional trade images here to illustrate my impressions of this plant and to convey its unusual beauty. A second flaw is that it is top-heavy; although heavy is not an adjective to describe a frothy, billowy cloud with cherry milkshake coloration. As is worships the sun, it bows down from its "waist". That is not a shortcoming if the plant was smaller, but since it reaches five feet in height in my garden and even taller in warmer climates, staking it is a requirement. Normally, I do not recommend plants that need this kind of care but this one is too beautiful to ignore.

In my clients’ gardens, I used a four foot stake and allowed the top of the flower-cloud to billow downwards. When the fluffy lavender pink clouds cascade, they create a soft, reverse vertical direction in the flowerbed. Gardeners who are able to position this plant so that it is backlit by the afternoon sun will rejoice with the ethereal effect that the lacy flowers create when the sunrays shine through them..

When researching this perennial, I came across an irreverent, but extremely clever, sales pitch for it. The people at Plant Delight Nursery, Inc. in the Carolinas are such humorous horticulturists, that I need to share their gem-of-a-description with my readers. The added, italicized commentary and translation are my own.

“Holy S...!  a censored, colloquial expression of intense, pleasurable astonishment with no polite equivalent. This giant meadow rue from French heuchera breeder, Thierry Delabroye popped up as a garden seedling  unplanned parenthood  resulting from a midnight rendezvous  an illicit intimate encounter  between the Chinese T. delavayi and T. elegans...oh, those hot French liaisons! The result is a 9' tall stalk,  well, 5 feet in USDA Zone 4  composed of lacy, deer-resistant foliage, the top 3' of which is a massive 4' wide   believe it!  cloud-like cluster of lavender-pink dangling flowers  like dense pink snowflakes  starting in late June (NC) and continuing until late summer.  It blooms throughout the month of September in USDA Zone 4b.  Because of the immense floral weight, the stems are more slanted than the politics on MSNBC,   it flops over  so a support structure of strong neighbors is suggested.  Don’t rely on the neighbors. Use a tall stake. 'Splendide' also had its tubes snipped (legal in France),  the plant is sterile and will not self seed. so don't worry about having unwanted meadow rues to support.  It’s so beautiful, I wish I had countless seedlings to share with others! Rich soils,  use compost!  like relatives, are highly recommended.”

Unlike the Species that blooms earlier in the season, in a pale pink color that fades in the sun, this variety holds its intense, twinkling shade of lavender-pink all season long. Its unusual flower, color, form, and texture offer the creative gardener an opportunity to think outside the box when situating this variety in the flowerbed. At the least, it is challenging fun; at best, it is an experience bordering on joyful.