Three years ago I started experimenting with planting on the street, in front of the early summer-blooming old rose bed some drought-tolerant perennials flowering in late summer and autumn.
I think the experiment was successful. In this year’s extreme heat and drought this bed got absolutely no watering, and yet its plants not only live, but are beautiful, proving to be drought-tolerant not only in the books, but also in the reality.
The first one is the plant in the left lower corner of the picture, Aster oblongifolius (syn. Symphyotrichum oblongifolium) 'October Skies'. At us it starts to bloom in late August, early September, and in contrast to most description, it does not require full sun, but also blooms beautifully in part-shade.
The grass next to the Aster in the first picture is in the left upper corner in this photo: Panicum virgatum 'Squaw'. Now it is at the beginning of its autumn coloration, later it will take on beautiful red tones. In the middle, a yellow flower: Solidago canadensis. It came here by itself. I like it very much, but it is so aggressive that I do not dare to put it in the garden. Here, in the street, above dry building rubble, however, it works perfectly. In the right lower corner of the image, a Perovskia atriplicifolia (at us it is usually much larger than what Dave’s Garden writes, at least one to one and a half meters high and large). It is one of the most drought-tolerant plants I know. Its airy shape and pastel grayish blue color makes every composition lighter and more sophisticated. It should be planted in a way to feel its pleasant, spicy scent as well.
Behind the Perovskia, another excellent, drought- and shade-tolerant (!) Aster: Aster ageratoides 'Asran'. (Though I must say that Aster oblongifolius tolerates drought even better.) On the following picture, the same plants in close-up.
As they spread very aggresively, I would never plant it in good conditions, but they are excellent on hard-to-plant places, bad soil, in shade (!) and dry areas.
Finally, in the foreground, a Heterotheca villosa (also sold as Aster 'Golden Sunshine, e.g. by the Mocsáry Perennial Nursery in Budapest), together with the Panicum virgatum 'Squaw', already seen at the beginning of the bed. As it is really drought-tolerant and long-blooming, it can brilliantly associated with grasses and other drought-tolerant perennials. It would be worth to plant it more often.