The late, great British gardener and writer Christopher Lloyd is in part responsible for my deep love of South American vervain (Verbena bonariensis). It was Lloyd’s book Colour for Adventurous Gardeners (Firefly, 2001) that introduced me to this plant, also commonly called tall verbena. Lloyd had it generously planted throughout the gardens at his home, Great Dixter, and his books, always laden with glorious photographs, featured many photos and references to the plant. I loved it on sight, and wanted to see it for real.
My first sighting of tall verbena came in the fall of 2006, when I travelled parts of the VIA Garden route from Halifax to Windsor, Ont. Many of the gardens I visited included this late-blooming annual or short-season perennial (hardy to Zone 7) in their late-season displays. In the years since then, I’ve been gratified to find V. bonariensis in more and more public and private gardens, and to find seed and transplants available more readily, too. Since it can regularly reach six feet (1.8 m), and utterly covers itself in slender, wiry stems bearing clusters of petite mauve flowers, it makes a marvelous statement in any planting, and offers a great burst of colour during the winding down of the blooming year.
One spring, I bought two six-packs of V. bonariensis seedlings and planted them as soon as the risk of frost was past. I did this rather than start from seed because I’m so busy in spring. Starting seed indoors tends to be an exercise in horticultural disasters, but that’s a story for another day. Plus, I wanted the flowers to come as early as possible. They obligingly started blooming in early July, and as of mid-October, were still going strong.
To my great delight, my new garden is also the recipient of seedlings from last year’s plants, which started blooming a few weeks later than did the transplants, but as a result I have clouds of mauve flowers all throughout my gardens. They provide a gorgeous contrast to the various tall asters, fall monkshood (Aconitum carmichaelii [Arendsii Group] ‘Arendsii’), Mexican sunflower (Tithonia rotundifolia) and ‘Sungold’ buddleia that are still performing like crazy in my Wolfville, N.S., garden.
Plant tall verbena in full sun for the best growth. Too much shade will make the plants a bit spindly and won’t give you as much bloom. If you have good winter drainage, you may get volunteer seedlings the following year. For those valiant gardeners plagued by Bambi and Thumper, tall verbena is deer and rabbit resistant, and also drought tolerant once established.
Pollinators love tall verbena, from species of bees and pollinating flies (bee mimics), to butterflies, including the cherished monarch. It makes a great cut flower as well, and, of course, cutting stems prompts plants to send out even more flowers.
According to other gardeners, tall verbena can be dried, although I have not yet tried doing that, mostly because my cats want to eat any dried flowers they find!