Verbenas are purple-flowered plants with immense value in ornamental, pollinator, and herb gardens. Tall verbena is a hardy specimen that sometimes escapes cultivation. Learn how to cultivate it and manage its spread with seasoned grower Jerad Bryant.Easy-spreading plants are incredibly valuable in the home garden. You won’t have to fuss over their soil quality, their nutrient needs, or how moist they are. They’ll thrive whether you cater to them or not!
Verbena bonariensis, or Brazilian vervain, is one such plant that spreads rapidly, readily, and without help from gardeners. You’ll spend more time pulling up its volunteer seedlings than you will caring for it! An herbaceous perennial, it’ll grow in the same spot from year to year and self-sow at the end of the growing season.
With two spreading strategies, this clumping wildflower is ideal for wild, open spaces. Let it fill empty cracks and crevices of your flower beds, or have it roam freely between your vegetables and lure pollinators to your crops. Verbena bonariensis is a clump-forming perennial with long, wiry stems. It stays low to the ground early in the growing season, then it sprouts tall-reaching flowering stems to attract bees, butterflies, and hummingbirds in late spring and summer. Native to Brazil and Argentina, this vervain thrives in warm regions throughout these countries. It sprouts amongst tropical and subtropical trees, shrubs, and similar perennials. Though native to South America, it’s popular as an ornamental garden species, and its weedy tendencies allow it to escape gardens. This Verbena species has naturalized in the warm, subtropical climates of North America, Asia, Africa, and Australia. It self-sows readily and resprouts from perennial roots in USDA hardiness zones 7 through 11. In colder climates, it grows well as an annual wildflower during the warm months.
This is one of many species that thrive on the continent. Many growers confuse it with the similar Brazilian type, V. brasiliensis. Though these South American verbenas are gorgeous and hardy, they are aggressive spreaders in the U.S. There are similar options native to the country that thrive in home gardens. Consider mixing Verbena bonariensis with native species like hoary and blue vervains. Verbena bonariensis sprouts clumps of rosettes in early spring. The leaves are deep green on top and gray-green underneath, with serrated margins. As the days lengthen and warm in spring, spongy, square stems emerge from the rosettes. They reach two to four feet tall and sprout flower clusters on their tips.
The flowers are small but mighty! They’re full of nectar and pollen, and they attract a wealth of beneficial insects and pollinators. The tiny blossoms are light pink-purple; they sprout from dark pink tubes to create a lovely, contrasting effect. After flowering, the pollinated blooms form many seeds that fall to the ground in the fall and winter. These seeds sprout into volunteer seedlings that will flower the following spring. The main plant will enter a winter dormancy, conserving its energy in its roots and crown.