What are the best taller sedums?
I have had Sedum telephium "Autumn Joy" growing here for 10 years. It has taken over a huge area, as desired; and reliably blooms every Fall.
what's your secret!? I planted AJ a few years ago in full sun and it just trudged along, eventually dying. Companion plants that did well included Achillea and Artemesia. Soil is well drained clay. Does it need moderate to regular water?
The area that this is planted in is between rocks with probably the best soil on the whole property -- a century of Oak leaves etc. The partial daily shade by the Oaks probably helps too. I was just out there a few minutes ago being amazed at how huge an area it now covers.
Maybe it depends on what you mean by "best".
If you're hoping for a plant that really does well all year in your California climate, the "tall sedums" of back east aren't your "best" bet.
The two common eastern types, S. telphium and S. spectabile, aren't dependable in most gardens. I have seen a few nice ones but none compare to their beauty in midwestrn and eastern gardens.
We have plenty of tall sedums that are almost "California signature" plants, doing extraordinarily well here:
Sedum 'Black Jack'
Sedum 'Postman's Pride'
Sedum 'Purple Emperor'
Sedum 'Samuel Oliphant'
Sedum dendroideum, S. praealtum
If you're interested in a tall succulent, you might also look at the flowering Kalanchoes and Cotyledons.
Do you know what Sunset Western Garden Book zone you're in?