The Gardener’s Delight: Delaying perennial cutbacks until March

The Gardener’s Delight: Delaying perennial cutbacks until March

Grama grass (Bouteloua gracilis ‘Blonde ambition’) is a welcome presence through winter. Photo by Kyrnan Harvey

By Kyrnan Harvey

At the High Line, the exemplary greenway planted over the abandoned elevated railroad on the west side of Manhattan, the professional horticulturists wait until March for the “cutback” of herbaceous perennials. The dry foliage and stalks gone to seed offer shelter, food and perching possibilities to birds. Leaving them uncut through winter also protects the dormant crowns of plants from winter cold and wind.

But there is a third reason practitioners of the New Perennialist movement delay until March — along with the ecological and the horticultural, there is also the aesthetic. The art of close observation has rewarded us with appreciation of the browns of winter: the lines, the textures and the patterns, especially with the white counterpoint of snow underneath and fresh snow draping the skeletal remains.

The 19th-century Irishman William Robinson was the progenitor of the movement that steered away from formal, geometrical, Victorian bedding-out schemes and garish patterns of hothouse flowers. Through his illustrated books, “The Wild Garden” and “The English Flower Garden” (readily available in reprints); his journal, The Garden; his famous garden Gravetye Manor in Sussex; and through his friendship and collaboration with his contemporary Gertrude Jekyll, he introduced many gardening traditions that today are synonymous with “the English garden” — herbaceous borders, mixed borders (small trees, shrubs, vines, perennials, biennials and annuals grown together in informal drifts), ground covers and rock gardens.

Robinson rejected the artificial, statuary, topiary, fountains and carpet bedding and extolled the naturalistic, the wild and the untidy. His inspiration was not Italian grandeur but rather the simple cottage garden: hardy plants from around the world naturalized to blend into their surroundings. “The best kind of garden grows out of the situation, as the primrose grows out of a cool bank,” he writes in “The English Garden.”

It is an aesthetic that discovers and appreciates the subtle beauties of the natural world in all its diversity near and far. Karl Foerster (1874-1970) was a German nurseryman and writer who discovered a great many perennials, not least grasses, and elevated their status within gardening cognoscenti.

Many of these are North American natives — asters, coneflowers, goldenrods, and most importantly, grasses — but it was European plantsmen, nurserymens and philosopher-gardeners (Ernst Pagels, Mien Ruys, Rob Leopold, Henk Gerritsen, James van Sweden, Wolfgang Oehme) who in the mid-to-late 20th century introduced and popularized many dozens of plants — and the naturalistic aesthetic — that today we take for granted and that is now known as the New Perennialist movement.

And it is a Dutchman, Piet Oudolf, who today is the most acclaimed and influential plantsman and garden designer. The planting at the High Line is the embodiment of his celebrated aesthetic, and is merely one of his many public gardens revealed in a documentary that premiered last November titled “Five Seasons: The Gardens of Piet Oudolf.” He has written numerous books but my favorite is “Oudolf Hummelo,” co-written with Noel Kingsbury. (Hummelo is his family garden in Holland started in 1982.) It is in his beautiful books (or his Instagram) that you will quickly appreciate the merits of delaying until March the cutback of perennials.

As winter drags on, I only just started to cut back the grasses to expose the pushing daffodils. I know of a gardener who uses a mower at its maximum cutting height, but I have Narcissus, Camassia, Allium and Eremurus visible already, so I use my gas-powered hedge trimmer, which makes really quick work of cutting down even the most beastly Miscanthus, and I can be careful not to step on the precocious perennials.

Nor am I in any rush to get to work on the late-winter pruning and cutback of summer-blooming shrubs like Buddleia, Caryopteris, Hydrangea paniculata and roses. I prefer to wait until late March, when any threat of arctic blast is past.

Kyrnan Harvey is a horticulturist and garden designer residing in East Setauket. For more information, visit