My Love for Verbena Bonariensis

By Elizabeth Scales, Master Gardener Intern

My favorite plant is Verbena bonariensis. Until a few years ago, I had never heard of this plant, nor had I ever seen it. It wasn’t until I was looking through a gardening magazine that I saw a picture that stopped me in my tracks. It was a picture of a large swath of tall, airy plants with a purple lavender flower. “What is that?” I thought. The plant was called Verbena bonariensis and this particular garden was in the southern United States. “Oh great!” I thought, another plant that would never grow in my Manitoba garden.

Verbena bonariensis (Family: Verbenaceae) has clusters of small purple flowers on long stems. Also known as tall verbena or purpletop, Verbena bonariensis is native to South America. In the 1700s, seeds were brought to England from Buenos Aires, Argentina.

Verbena bonariensis is a perennial plant in zones 7-11 but is an annual in cooler zones. In California and Texas, Verbena bonariensis is considered a weed and it has also naturalized in Australia and South Africa.
As previously mentioned, Verbena bonariensis is a tall plant growing three to six feet tall. It is multi-branched and does not fall over, meaning there is no staking needed. The flower itself is only one-quarter inch across.

Verbena bonariensis blooms from July until frost. Since it is so airy looking, it can be planted in the middle or at the front of a garden border. It is best planted in masses where it draws the eye and is more noticeable. Use Verbena bonariensis in a cut flower arrangement as the flowers are long-lasting.

It wasn’t until I read a Winnipeg Free Press article in 2018 by Colleen Zacharias that I reawakened my interest in Verbena bonariensis. Ms. Zacharias’ article was focused on Matthew McCarthy, who at that time was a photojournalist for a newspaper in Ontario. Mr. McCarthy takes photos of plants but admits that “plants in decay are often more interesting to him.”4 Accompanying this article were several pictures of plants past their prime but captured by his camera with artistic flair. Mr. McCarthy continued to talk about his garden “with many different types of seed-grown plants.”4 He had recently started his own business, the Apocryphal Seed Company. Intrigued, I went to the company’s website and found (you guessed it) seeds for Verbena bonariensis.
Now I hate to admit this, but I have been a gardener for over 30 years, and I had never started my own seeds indoors. The thought of seed-starting seemed complicated… grow lights, …damping off, etc. It was easier to go to the nursery and buy plants and I took the easy route.

However, I had never seen Verbena bonariensis for sale at any garden centre and I had to have this plant. I ordered seeds from the Apocryphal Seed Co. and borrowed a grow light from a friend. I was ready.

The seed packet stated that I should start the seeds 8 to 12 weeks prior to last frost date. I started the seeds in the third week of March, and I used a 9” by 6” tray filled with moist seed starting mix. The seeds are so tiny that I sprinkled them haphazardly over the top of the soil and then applied a very thin sprinkling of seed starting mix over the seeds. The seed packet stated that they should be germinated in the dark, therefore I could not place the tray under the grow light. I placed a magazine on top of the tray, and I watered the tray from the bottom. Then I waited. After a week, I peeked under the magazine. Nothing. The days went by and turned into weeks. After three weeks, I saw green. I kept the magazine on top of the tray for a couple more days, hoping for more germination. At this point, the magazine was removed, and the tray went under the grow light. I had a small fan blowing across the seedlings and I ended up with 12 healthy plants that I transplanted outdoors in early June in full sun. I planted them in groups of three for maximum impact; each plant was planted 12-18 inches apart and were planted next to my white Annabelle hydrangeas and David phlox. I had a beautiful show over the summer and people passing by would often point to the Verbena and ask, “what is that?” The Verbena bonariensis grew three feet tall in my garden.

In the fall, I left the seed heads on the plant and the next spring I had a few volunteer seedlings spring up. I was able to easily transplant these seedlings around my garden (again in groups of three or more). If you want to attract wildlife to your garden, include this plant since butterflies and other insects are attracted to the nectar that is found in the tiny lavender flowers. Birds eat the seeds in the fall. If you have a cottage-style garden or even if you want something different, include this plant.

What have I learned?… seeds have different requirements to germinate. Some need light and some need darkness. Who knew? Read the information on the seed packet and do some research online for more information. I also know that I will not be growing flats and flats of seedlings under multiple grow lights. This seems like a lot of work, and I envy people who can do this, but just growing a few plants each winter will make me happy. My attention now has been directed to native plants and this winter I plan on growing Purple Prairie Clover, possibly as a winter sowing project.

Apocryphal Seed Co. does not appear to be in business any longer. However, there are other seed companies offering Verbena bonariensis seeds for sale.

In the summer of 2022, I went to Assiniboine Park to see the gardens at The Leaf. In one section of the garden, I saw a plant that made me smile… Verbena bonariensis.

Photos by Elizabeth Scales

Published:  March 2023