I don't have experience with that particular species of Agastache. I did have a wonderful one that thrived in my front yard, but attracted too many bees for that location. I moved it, and it was fine for a year, but then died.The second site was much sandier and gravel-ier, so I wonder if you should add compost and not gravel.

I haven't bought any penstemon, and those I tried to grow from seed never made it, so I can't help at all, there.

I'd say you have exactly the right place for agastache, as long as you don't have heavy rains OR you can provide excellent drainage. I'm on the border of Z7, in the high desert of the Southwest. We have very poor soil, intense sun, high heat and low rainfall. Several agastaches are native here, so if your conditions are similar you should be fine. I grow several named varieties as well as species, but not Acapulco Rose. I do have Acapulco Trio and I would guess it is similar. Mine are about 30" high and wide and just starting to flower. I got mine off a damaged plant table last year for $3, so I'm lucky it's growing at all.

Penstemons are more cold hardy and generally do better with less heat, but several grow well here. They also want lean soil, low rain, good drainage and a fair amount of sun. I don't know your variety, and there are so many members of the penstemon family I don't know if my experience will be the same as yours. I have p. rostrifolius, erectus, palmeri, pinifolius and Dark Towers. All are in full sun or hot afternoon sun. All seem to do well. I had a p. pinifolius die last year but I put in another one this year and so far it seems to be fine.

Cheryl

I have a number of agastache cultivars but over the years have found Agastache foeniculum 'Golden Jubilee' to be the heaviest self-seeder/repeat performer. It has returned reliably in my part sun sandy loam since 2008 or thereabouts.

Penstemon digitalis 'Mystica' has been the best-performing beardtongue in my various garden beds, in both full and part sun. I grew more than a half dozen other penstemon cultivars from seed via winter sowing but none have thrived to the same extent as 'Mystica.'

I have both Penstemon and Agastache growing in the same part sun garden bed. The soil is slightly acidic sandy loam. I can't guarantee they'd perform the same way in your garden but have enjoyed them in my own.

The link below takes you to a list of Agastache cultivars at the Missouri Botanical Garden website where you can access more specific information.

Here is a link that might be useful: Missouri Botanical Garden

I have found excellent drainage to be the most important factors for both agastache and penstemon.

I have grown both Acapulco Orange and Rose. They are both very floriforous. Here's a picture of Orange from last year:

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