Vernonia is pretty tough; I've got mine in a fairly dry spot and it does fine. How about Joe Pye weed? They're used to dry, too.

edited to add: And beardtongue, too - they like dry. Sneezeweed? Zizia?

In our area, Chrysopsis mariana Maryland Aster grows in dry sun along with the butterfly weed. The ones mentioned above here would need a little more moisture if you plant in the spring. Ga. aster, other plants formerly known as asters, are fine, too, along with Solidagos, Helianthus. I find planting in the fall for the Penstemons and Joe Pye gives good results. Starting in late spring, if you are not going to water regularly, is not good in our sunny spots.

Grasses are good as well. I particularly like the combo of sideoats grama and butterfly weed. The grass adds structure and it's nice to see the butterfly weed blooms through the arcing lines of the grama spikes.

I like purple plants with it. My Liatris is nice. I also have obedient plant, but it may be too aggressive. Mine is in a dry spot which keeps it in check. My monarda dydima and purple coneflower also combine well. Coneflowers volunteered and I grew the monarda from seed.

Perennial salvias? The purple ones would be a nice contrast. Some can reseed enthusiastically, but shouldn't be a problem in an area that size.

Martha

I have found Echinacea tennesseensis (Tennessee Coneflower) and Liatris aspera (Rough Blazing Star) to be good companions with Butterfly Weed. I'm also a big fan of mixing in some of the shorter native grasses - Sporobolus heterolepis (Prairie Dropseed), Schizachyrium scoparium (Little Bluestem), Bouteloua curtipendula (Side Oats Grama) - not only attractive, they really hold the soil well on a slope.

Joe Pye Weed is a wonderful native, but I would suggest planting it at the bottom of the slope where it stays damp. It will thrive in damp soil.

Wow, thanks everybody. We have Joe Pye available to divide and transplant, as well as black-eyed Susans and coneflowers. I love all these suggestions, now I just need to sort out how to propagate them. Our native plant society only has one sale a year but their prices are steep. Am looking for sources of seed; preferably with seed originating from the Gulf or the SE. This is an extremely hot part of Virginia; the climate is closer to that of Charleston SC than it is the rest of our state! We are about 40 miles inland on the coastal plain north of Great Dismal swamp.
This new native planting is on a bank in the local arboretum, not close to any water source. So everything will need to be appropriate to our zone 8 climate. So this planting is a natural one, NOT a garden bed.
I am growing Culver's Root-- Veronicastrum-- and hope to collect seed from it this year. It's a thirsty little devil but so beautiful!
Question on salvias: anybody had success growing these from seed, and which ones?

Native Salvia coccinea is easy to grow from seed. If you start early, say first part of March, it will bloom that first year. For me it is an annual, but folks tell me that it reseeds in slightly warmer climates, which sounds like your area. There are lists for coastal NC, probably your area, too. I can email them to you if you write me off list.

Salvia azurea was super easy to start from seed. I winter sowed it last year in milk jugs and had way more than I needed. Not that it needs cold stratification, but that's when I was starting all the other seeds and so I just did it then. It flowered the first year on (floppy) single stems and I saw bumble bees on it frequently in late summer. This year it's filled in a lot more, should put on a nice show.

It doesn't look it's strictly native to your area but it is in SC and GA.

Woods Tea, I cut my Azure Sage back in early summer, sometimes I do it again in mid summer depending on how much rain we get, makes for a much less floppier plant that is thicker with more blooms. Last year with one trimming the bloom stalks were up to my chest. In the wild it grows much smaller than it does here in my city soil. At the History Museum there is a large solitary specimen planted in a big extensive long curved all native plants beds and it was extraordinary. I wish like anything I had a prime spot like that. I saw it from a distance last fall and knew immediately what it was, the thing was enormous and surrounded by several feet of nothing else at the very end. Of course, I had to walk over and take a closer look. By the way, I dug out and moved my whole plant last fall, it didn't even seem to notice.

Any salvia I have tried grow has been very easy from seed. The Salvia greggi self sows but they root so easily you can get faster plants that way. Meadow sage is easy from root divisions and the plants are common at the package stores. Salvia regla came up easy but it wasn't winter hardy here, it would be in zone 8. Salvia coccinea is an ugly plant and the foliage stinks but those always self sow prolifically, I let them come up in a difficult shady area. Cedar sage is somewhat aggressive in seeding but makes a good ground cover in shady areas. Big Red Texas sage (S. penstemonoides) is a big impressive plant that will bloom the second year and its also easy from seed. Mealycup sage is a good seeder and also easy.

how about some red current they can take some dry soil , but prefer damp and bloom early spring when there is not much food for bees butterflies and hummers , and you can eat the berries also

barbarag-happy, I can send you some liatris spicata seeds. They love to start.

If you mean Ribes rubrum, it's not native to the US. There are numerous native Ribes species, but I know that in some parts of the country, particularly the Northeast, some of them are illegal to plant because they're hosts for white pine blister rust.

And also obedient plant, but they don't seem to want to germinate for me.

no

Ribes sanguineum

I would love some liatris spicata seeds if you have some to spare

Always interesting to see what is approved/not approved and what is easy to grow or not in different parts of the USA. In NC, we have at least four different sections, so just because something is listed as native here doesn't mean it will do well for me in the Piedmont. And even the Piedmont has micro climates.

Have a Rhodie I brought down from the mt. 20+ years ago. This is the first year it has bloomed, and it was a wow! I guess it finally decided to flourish here since it wasn't going back to the mountains.

Nell, I found obedient plant in an old perennial border here. This fall I'll transplant some towards the bottom of the slope where there's some moisture. The Joe Pye weed will shade it but I'll bet it won't mind!

Wisc, what works in practice may not work in theory. Mine have been together 5 years and both orange milkweed and obedient plant are gorgeous. Very little weeding has been required and water is what nature gives us in northern Virginia. My moonbeam coreopsis kicked the bucket. The Monarda fistulosa that I started from seed next to it is doing well as well.

WI Tom, good point-- our phystostegia v. is in moist shade with hostas. It will be a good companion for the A. incarnata at the foot of the bank, with similar coloring. Coreopsis lanceolata is the best one here, but clumps tend to expand rapidly and then disappear. Blanketflower likewise-- swampy coastal areas however hot cannot fool these plains type plants. That won't keep me from trying them but I'd prefer something that can establish and thrive on the dry bank without being replaced. While dry, it is a heavy clay soil so we have some latitude. I should be able to get some of these started indoors and set the plants out in early fall. Hopefully they'll overwinter; we have 2 very cold winters behind us so I'm thinking we're due for a mild one!!!

Woodstea: Sideoats grama, oh yes! I definitely want to try that.

I also agree with the above recommendation for little bluestem. Has no problem with dry sites, plus it will be low when the milkweed is blooming, then it has nice structure later when the milkweed is in decline.

Solidago puberula might also be good, though I don't have personal experience since it's not native to my area. I think it's especially valuable to have late season bloomers for nectar sources. Perhaps Liatris pilosa var. pilosa? Symphyotrichum concolor?

How about Baptisia tinctoria? I also try to have a few legumes in every bed...

Speaking of Solidago, S. speciosa is a fine and dandy one for the more upland, drier site. Like where the Asclepias t. would like to be situated.

+oM

I like purple prairie clover (dalea purpurea), aromatic aster (Aster oblongifolia) liatris. Liatris has the advantage of being a bulb that's easy to buy in bulk and occasionally sold cheap and Lowes. Purple prairie clover is a nitrogen fixer. Also, Baptista Australis is easy to find.

Aster oblongifolia