I sprouted my own Verbena bonariensis plants from seed this year. I used to buy robust bedding plants each spring from a garden center, but they went out of business last year. The pretty, purple flowers attract butterflies and have a sweet scent.
Verbena bonariensis is a perennial in Zones 7-9 and can be grown as an annual in colder zones. The plants grow 3 to 4 feet tall, but you can stick them anywhere in the garden or a flowerbed because the stems have very few leaves. If you plant them in the front row of a flowerbed, the flowers will appear to float above the shorter plants. And they are so skinny, they take up very little space.
I was a little worried that my experiment was going to fail. First I had trouble getting the seeds to sprout. I reseeded a couple of times. I finally cobbled together about 10 plants. They were pretty well-behaved for the next couple of months, but just before I was going to plant them in the garden in late May, they turned a sickly shade of yellow.
I planted them anyway and whatever nutrient they were missing must’ve been in the garden soil because they quickly rallied. By mid-summer I couldn’t tell which were my plants and which were volunteers that had sprouted from previous years’ plants.