Back in July, I noticed this little vinca volunteer growing in a joint in my concrete.
A month later, it looked like the above picture. It was thriving away with no care whatsoever.
Now it looks like the above picture. It's blooming beautifully, keeping good form, and still getting no care at all. Vinca's are great for volunteering. They are about the most drought resistant annual on the planet, so require no supplemental water at all. They have a very pleasing form and bloom continually till fall. I haven't seen any bug pests on them, but they can get fungal diseases, especially if planted too early. The LSU AgCenter advises to plant them no earlier than May (in the Deep South) for them to thrive best. This is perfect for those of us who have cool season annuals up till May and don't want to pull them out early.
Here is a close-up of a bloom. My only complaint against vincas is that they are not attractive to butterflies, bees, or hummingbirds. Nevertheless, if you want a splash of carefree color in a place where you don't have to water, this is the plant for you. They appreciate hot, full sun and good drainage. This is perfect for an edge along a concrete walk or driveway.