Mix and match to your heart's content!
Planting a couple of containers for late summer and early fall is a great antidote to a dry summer. Some gardeners leave plants like these in containers for as long as a couple of years; others never plant them in the container in the first place - just place plastic pots directly in the container. You can easily plant all of these in the ground in late fall or early winter so long as the ground is not frozen. Whichever method you prefer, it's all easy.
The Flower Palette
These pink, lavender, blue and yellow flowers have a variety of shapes and foliage textures. All tolerate fairly dry soils and like full sun. It's totally mix and match - you can't go wrong! These are all cultivars except for the straight species wild petunia. You could easily use straight species of all of these perennials, the best native plants, for these containers.
Plus an Architectural Statement
The awkwardly named rattlesnake master (Eryngium yuccifolium) is actually a tame plant with mildly spiky foliage - nothing crazy to fear. It's an excellent straight species perennial to have in your garden for late summer and fall as a statement. The architecture of the blooms on two to three foot high stems and the blue tinge of the yucca like foliage add an exclamation point wherever it is used.
Plus a Grass
There are a number of native grasses one can add to a container: little bluestem (Schizachyrium scoparium), muhly grass (Muhlenbergia capillaris), prairie dropseed (Sporobolus heterolepis). I had a cultivar of switch grass (Panicum virgatum "Shenandoah) -- pretty large for a container but since it is quart sized now, fine for a temporary location. It also prefers moist soils but will tolerate drier soils and, for a short term spot in a container, drier conditions will be fine.
Less is More
A no fail approach that always looks good for containers is combining several of the same plant in one container. Whether it is asters, blue hyssop or black eyed susans, it is all going to look good. The down side is once the blooms fade, the entire container fades.
To get a longer period of bloom with a simple design, try combining perennials with similar flower colors. Here, joe pye weed, obedient plant, phlox 'Jeana' make for a container in pink. The obedient plant is just beginning to bloom and will carry the container further into fall with color. The last plant here is added as a "draper." In native containers, one of the best ways to get a draping effect is to add wild petunia. It has a long bloom time, grows well in sun or part shade and will grow over the edge of your container. You could also go yellow here with goldenrod and black eyed susans.
Any combination of these perennials can give you an informal meadowy vibe. Here, adding switch grass to asters, wild petunia and joe pye weed really does it.
Rattlesnake master makes the container far more artful. The contrast in foliage adds a whimsical touch.
While I am not sure of the exact number of potential combinations here, I do know they will all look good! Those of you with eagle eyes will spy the mix of invasive english ivy and vinca at the base of the tree in the background -- the dreaded duo. Hoping to get to that very soon! Isn't that one of the great parts of gardening? Always something to do and look forward to!