Native plants

In Love With Blue Verbena

Fleurs bleu violet de la verveine hastée.
Spikes of tiny flowers of blue verbena. Image: Julie Boudreau

This spring, the National Garden Bureau announced that 2022 would be the Year of the Verbena. Their idea was clearly to present the annual verbena, the one that we grow in our hanging baskets and decorative containers. However, it made me want to tell you about one of my favorite verbenas, blue verbena.

Blue verbena in a natural setting.
Blue verbena in a natural setting. Photo: Julie Boudreau.

A Native Plant With Ornamental Qualities

Yes, blue verbena (Verbena hastata) is a widely distributed North American perennial. Also called American verbena or swamp verbena, its distribution extends from southern Canada to Florida and New Mexico. It’s found in damp ditches and on grassy banks where it forms small colonies. Well, usually. Because it’s also found on the edge of rocky slopes and in drier soils.

It’s an upright grower and can reach up to 6 feet (180 cm) in height, although it generally remains more in the 3 to 4 feet (75 to 120 cm) range. The leaves, rather slender and with a rough texture, are sometimes used in traditional medicines (but don’t confuse this plant with common verbena, V. officinalis, the usual medicinal verbena).

Blue verbena has all the qualities you’d want in an ornamental plant. For example, it fits perfectly in the background of a perennial bed. Plus, the plant is sturdy and the foliage remains beautiful all season round. But what about the flowers?

Unique Bloom

Of course, it’s blue verbena’s blooming habit that charms me the most. Between July and September, the plant produces multiple clusters of upright spikes. Starting from the bottom and moving up, the small violet-blue flowers pop open one after the other like popcorn, rarely more than six or seven blooms per spike at a time. I find this gives it a certain humility. I mean, this plant is miles away from a big fluffy peony! Its constant yet modest flowering impregnates blue verbena with a sense of delicacy.

Blue verbena flower spikes.
Spikes of tiny flowers of the blue verbena. Photo:: Julie Boudreau

The flowers are visited by numerous pollinating insects and butterflies. And beekeepers consider it to be an excellent flower for honey production.

Naturalize It… Massively!

I consider this plant to be the queen of the naturalized prairie. It blends perfectly with other wild flowers such as swamp asters (Symphyotrichum puniceum), goldenrods (Solidago spp.), St. John’s worts (Hypericum spp.), white snakeroots (Ageratina altissima) and mulleins (Verbascum thapsus). It’s also ideal for revitalizing shorelines, pollinator gardens and revegetating ditches. And it’s deer resistant too!

Swamp aster with pale lilac flowers.
The pale lilac flowers of the swamp aster. Photo:: Jesse Rorabaugh, Wikimedia Commons.

Blue verbena will develop vigorously in full sun, especially in moist soil, its preferred habitat. That’s where it will best demonstrate its excellent cold hardiness (USDA hardiness zones 2 to 9). However, in the warmer and drier parts of its range, blue verbena tends to behave more like a short-lived perennial or even an annual. Luckily, the plant reseeds itself and can therefore find its own place in the garden over the years.

To avoid what could be a lot of unnecessary weeding, I recommend using it in a naturalized garden rather than in a well-maintained border. That way, you can let it grow where it pleases!

Even though it self-sows, blue verbena is far from being invasive. It just comes up modestly here and there. Looking through other author’s remarks, I found that nobody seems to complain much about it getting out of hand. On the contrary, they often recommend it as a good choice as a remplacement for other invasive plants!

Julie Boudreau is a horticulturist who trained at the Institut de technologie agroalimentaire in Saint-Hyacinthe, Québec. She’s been working with plants for more than 25 years. She has published many gardening books and hosted various radio and television shows. She now teaches horticulture at the Centre de formation horticole of Laval. A great gardening enthusiast, she’s devoted to promoting gardening, garden design, botany and ecology in every form. Born a fan of organic gardening, she’s curious and cultivates a passion for all that can be eaten. Julie Boudreau is “epicurious” and also fascinated by Latin names.

1 comment on “In Love With Blue Verbena

  1. marianwhit

    Love it, spreads a lot, but easier to pull than most weeds. Plus it is a native plant! Yay, thanks for putting the focus on native verbena! Verbena has speciated, meaning that members of the genus have evolved over time to become many species of that genus found in almost every location in North America! How cook is that? So, if this verbena is not native to your area research the natives to see if you can find one in your area. This plant is a win-win…beautiful in mass plantings, and always full of interesting activity!

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