I think it may have more to do with the species. My 'May Night's start to get shaded around 2:00 to 3:00 (depending on which one) and they are all completely upright. They are in lean-and-mean soil. 'Cardonna' is only year 2, but it appears that it will be very upright. It is in rich, moist soil. 'Marcus' is a terrible flopper. It is in lean to average soil and good sun. I used to have a white one, possibly Snow Hill, and it flopped, good soil, good sun. So for me the floppers are S. nemerosa (with the exception of Cardonna). S. sylvestris seems stronger, but I only have one. Not conclusive, but may help point more to species than conditions.

Kevin, I had the same results with the S. Freisland (a dud) and all the Superba types leave me disinterested because they are sold so commonly in places like Home Depot so they seem on the same level as marigolds to me now. Any deep purple seems to disappear in my garden and its not my favorite. I do well with Salvia 'Hot Lips' and the greggii types here but they are only hardy in the warmer zones, I think zone 6 is the limit. They do root extremely easy and you can winter cuttings if you want to go to the trouble, they don't seem to resent being dug up and moved either. I have some new ones started from cuttings I took in fall that are now rooted indoors to add more of the new colors I got last summer. Salvia 'Hot Lips' grows really fast and will form a good sized bushy plant in a single season and I think you could just about treat it as an annual in cold areas and use new cuttings each spring. I added some Cedar Sage last fall under a tree hoping for it to make a ground cover and grew Mealycup sage and Coccinea, these all come up easily from seed and naturalize well. Some years back I grew clary sage and I am thinking of adding it again, I like the bracts which makes it ornamental for a very long period in summer even after the blooms are spent. J.L. Hudson has one called 'VATICAN CLARY' that has "large white flowers tinged with pink. Nice!" I am thinking of ordering seeds. I'm also looking at 'KASHMIR SAGE' and 'SILVER SAGE' in the catalog. I want to try S. alpiana but at best it would preform as a short lived annual here. I read it grows fast and seeds about so that might work. For $2.50/pack I'd gamble on it. I'm also looking at the native S. hispanica 'CHIA', its a native annual endemic to California, I like those funky ball-like flower heads and it would be a fun returning annual each spring.

My 'Caradonna' (also a nemorosa) sends out new blooming shoots below, and on either side, of the old blooming stem, so I just remove the old blooming stem down to the next set of leaves and/or stems. Brenda

You might also consider another agastache, such as 'Purple Haze' or 'Black Adder' . Blooms all summer, drought tolerant, deer, rabbit resistant. Loved by butterflies. You may be pushing the zone, but since you grow 'Blue Fortune', these might work for you. I have 'Caradonna' and it is a great salvia, but requires cutting back at least 3 times in the summer for blooms. An annual salvia, like farinacea 'Victoria Blue' is beautiful. I grow it with just about anything, including my roses. It is spectacular. Cameron Here is a link that might be useful: six of my agastache varieties