Name: Verbena bonariensis aka tall verbena.
Type of Plant: On the Cape and Islands this is a self-seeding tender perennial. In slightly colder places it’s a self-seeding annual, and in warmer climates a true perennial.
Why I Love/Hate this plant: There’s so much to love about this plant that it’s hard to know where to start. First of all, it’s tall and thin so it fits well between other perennials and annuals…it plays well with others! Secondly, the thin stems that are topped with purple flowers are great in bouquets, so a must for the cutting garden. Third, in this area, once you have it you always have it…it seeds itself and you don’t have to do anything other than pull out the excess in early June. Fourth, although who’s counting, it flowers from late-June through October and finally, the butterflies love it!
A Word to the Wise: If you don’t like editing out self-seeding plants, this isn’t for you. But if you don’t mind pulling out the excess in June, you’ll be blessed with areas of purple flowers for the rest of the summer and into the fall.
Grow these in full sun and well drained soils.
Don’t spread mulch where you want these to grow. They will spread seeds, but if you cover those with mulch they won’t germinate. So leave the areas where you desire this plant uncovered.
If you can’t find plants in the early summer in garden centers, this plant is easy to grow from seed, but in my experience it’s best if you plant it in pots in late February and then put those pots outside in the cold all through March and April. That will help more seeds sprout. In May, transplant them into the areas you want these to grow and you’ll have tall verbena for years to come