Anonymous wrote:I would consider:

compact forms of native geranium aka cranesbill, like "Johnson's Blue" (https://www.gardenia.net/plant/geranium-johnsons-blue-cranesbill)

shorter varieties of native asters, like "Raydon's Favorite" (https://www.burpee.com/aster-raydons-favorite-prod002855.html)

Phlox or amsonia would work too, as would native salvia, native columbine, echinnacea with a color that contrasts the catmint.

OP here, thank you! I forgot how much I like asters, and appreciate you linking to a shorter variety.

I would consider:

compact forms of native geranium aka cranesbill, like "Johnson's Blue" (https://www.gardenia.net/plant/geranium-johnsons-blue-cranesbill)

shorter varieties of native asters, like "Raydon's Favorite" (https://www.burpee.com/aster-raydons-favorite-prod002855.html)

Phlox or amsonia would work too, as would native salvia, native columbine, echinnacea with a color that contrasts the catmint.

Anonymous wrote:I think height is the main difference. Otherwise the flowers look pretty similar- flattish heads made up of many tiny flowers. Yarrow is maybe 24” tall? Joe our is very tall but little Joe is more like 3 ft? I think atonecrop is a ground cover?

OP here, this is the conclusion I came to. Based on a variety of factors I think I'm going with the stonecrop sedum Autumn Joy to complement the catmint. If anyone has suggestions for a third option I'd welcome them!

I think height is the main difference. Otherwise the flowers look pretty similar- flattish heads made up of many tiny flowers. Yarrow is maybe 24” tall? Joe our is very tall but little Joe is more like 3 ft? I think atonecrop is a ground cover?

I agree on the stonecrop sedum. So easy to grow and it spreads like crazy, but you can also pull it out by hand no problem if it gets to be too much and just add to your compost. Stay away from Creeping Jenny, which grows just as fast and looks pretty with its light green leaves, but it near impossible to clear out once you have it. I so wish I never put it near my garden.

Yarrow should bloom earlier than the browneyed susans and the sedum will bloom at the same time.

I love yarrow and would probably go with that for a longer blooming show