planting on bedrock

by Kate
(Kearney, Ontario)

Can you recommend plants that can be planted on -basically bedrock.

I am a designer - have a project that requires some planting in an area that is pure bedrock - there is some natural stuff but nothing is really lush - and this is a public place (cemetary)

I love gardenning myself and have had lots of luck with creeping phlox on my rock walls and in rock crevices on our property - see you recommended using this too. Another one I have a lot of luck with is Dragon's blood - sedum - seems to thrive on rock

What method would you recommend for planting? I have found by just looking for crevices, filling in with some soil, plant the wait.

Do you have any suggestions? ,,,for this and other plant materials - zone 4

Thanks
Kate

Doug says the list of plants for this kind of condition is huge (way too large for this kind of answer)

The "trick" is in the site preparation (isn't it always?) :-)

Take a tool and excavate the major cracks to remove rock/pebble rubble. Fill it with a decent topsoil. You won't likely get all the way down into the crack but you will be able to get down a few inches or more.

If the crack doesn't go very far (it's not a real crack) then you can use the super-tough plants such as the sedum/sempervivum etc. If you can get down 4-6 inches and you're not at the bottom of the crack, the list gets almost endless.

The trick here is that the hardiness is going to be site-specific. But these guidelines will help.

1) Any plant that's recommended for a green roof will likely survive in this environment.

2) Any perennial with a hardiness of zone 3 should be fine (and that would include such things as dwarf iris, daylilies etc)

Those two "general" guidelines will get you started - plant lists are literally impossible unfortunately - I used to grow a great many alpines for this kind of condition and offer them in my specialist nursery; the problem is they're specialist plants not often found in garden centers or nurseries because the demand is so small. The Ontario Rock Garden Society or North American Rock Garden Society should be able to help you with sources if you get stuck.

Good luck