We had a brick patio buried beneath our little garden when we moved in. Daylilies and hostas were growing like crazy in full sun with no care at all.

For 8-12" I would recommend using annuals. If you don't want to grow them every year, pick some that are good in self seeding.

Or use hardy or half-hardy annuals so you can sow the seeds early. This might mean a little work each year, but the plus side is you can change your design every year. :)

Thank you very much for the input. I don't know a thing about sowing seeds (yet) but I love the idea of daylillies and hostas around the fountain. I will give them a try!

Hmmmm - trying to remember from when I divide perennials -
I 'think' that the following all have fairly shallow roots - black eyed susans (rudbeckia), shasta daisy, corepsis zagreb, garden phlox, monarda, achillea, perennial geraniums... if your soil depth is 12 inches, I think most of these might be okay (?). However, you also mentioned possible drainage problems - can't talk about that, as I have very well drained, sandy loam....

of course, as already mentioned, annuals would have shallow roots systems...

Good luck!
Beth

I double dig beds to about a foot. Below that is compacted clay, if they are lucky. Bedrock if they aren't. Most perennials don't have any trouble with the conditions. They just don't go down that deep. Blue fescue specifically is one I have growing on rock.

So what is the real problem, drainage?

Once you figure out the real problem, then you can plant things that can deal with it. Until then, you are just groping in the dark.

Bog sage - salvia ulignosa
Monarda
Perennial ageratum
Itea virginica 'Little Henry'
Canna (may have to lift in winter)
Butterfly Ginger (may have to lift in winter in your zone)

Those all like moist, even boggy soil and full sun. You'll have to check zones as I'm in 7b. All are even deer resistant, if that's an issue.

Cameron

All type of plants that are Suitable for growing in containers will work.

The link below may be useful, it is search for all containers plant available at davesgarden site.

Here is a link that might be useful: Suitable for growing in containers