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

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Entries in staking pl;ants (1)


Thalictrum Hewitt’s Double is a Singular Sensation

Thalictrum Hewitt's Double floating over the partially spent September flowerbed.The tall, frothy Thalictrum that grows in the flowerbed on my front lawn is in its third year of maturity. As one can gather from the photo, it is a conversation piece. Everyone thinks that it’s a tree. No visitor to my home, or neighbor on my street, has ever seen such a delight for the eyes. It touches the admirer in a profound way.

I first discovered Thalictrum, the species, about 18 years ago, when I purchased over 100 seedling perennials, all of which had plant tags that indicated  flowers in pink or flowers in blue. At that time, Thalictum aquilegifolium, was an unknown entity to me. However, since it promised to provide pink blooms, I added it to the assortment, without a second’s thought. I was eager to be surprised.

Over the years, this species perennial, a very different-looking plant from the Hewitt's Double variety, would grow successfully and fully easy-care in my back yard garden. Tall and upright during the months of June and July, its stately, elegant pale salmon-pink plumes appeared iridescent in the shade but faded in bright sunlight. These feathery heads added an ethereal mood to my garden. When allowed to grow and mature without propagation, they created a grove of pastel softness suitable for any fairy tale illustration.

The species delivered such an impact to my soul that I was motivated to seek out other varieties. Almost 15 years later, A. Hewitt’s Double, a Thalictrum with a longer bloom period  [June to late September] appeared in some nurseries and I decided, this time, to plant it on my front lawn, where growing conditions seem to pamper perennials more than my back yard does. I expected some similarities with the species, but those are few.

Closeup of Hewitt's Double flower head.One characteristic that sets this plant apart from others is its translucent lilac colored flower heads. They scintillate in sun – especially when they are backlit – and glow in part shade. These visuals create a nearly supernatural mood in the garden. What a bonus!

Another unusual characteristic about Hewitt’s Double is that it cannot grow upright, even with the help of heavy-duty stakes, which are unquestionably necessary. Its flower heads grow in such a precarious position, that heavy rain and strong wind will cause the heads to crack off from its otherwise formidable stalks.

Up until this year, I expected that staking the plant in a delphinium style, i.e., one very tall support behind the plant, would be sufficient to keep it from buckling over. It wasn’t!  By the end of summer, I had added an additional three stakes behind the first, each one taller and thicker than the last. None was able to prevent the plant from bowing over to catch the sun. And combined, they were no match for nature's pull.

Because several tall broomsticks together were no match for the pull of this plant, I resorted to using a one-inch wide steel I-bar, 6 feet tall. The perennial became upright as soon as I inserted this metal stake into the earth with the help of a mallet [it took at least 200 whacks to secure it in place] and tethered the plant to it. For that solution, I must thank my lawn service staff who came up with the idea and gifted me with this repurposed steel object.

Especially when held upright, an astute garden designer may have noticed in the posted image that the proportions of this perennial are not suitable for both the narrow width of the flowerbed and the height of the neighboring plants.

Hewitt’s Double towers awkwardly over the other perennials because none of them grow tall enough to anchor or integrate it into the color scheme. This impression, of one plant floating above the others, while it creates movement, also creates instability which makes me uncomfortable. That is reason enough to lift and place it elsewhere.

The rose patch that grows directly behind this flowerbed, and up against the elevated veranda, appears to be a better location. I intend to move the Thalictrum to the left of the pink Rose Bonica that appears in the far background.

I hope that both this rose, along with Rose Carefree Wonder to its right, will provide sufficient height, volume and shape to weave Hewlitt’s Double into the overall garden design. I expect that the iridescent lilac color of this unusual perennial will appear enhanced and even more amazing when it blooms next to the rich baby-pink of rose Bonica.