Shallow rooting plants for a border, suggestions please.
As well as my own garden I help a couple of my neighbours with theirs. I am just about to finish the creation of a wide and quite long border in one of them.
The problem is that the topsoil was very thin with a layer of hardcore underneath, which I don't have the time or resources to remove. I did remove all the topsoil and sieved it to remove all the stones and removed a little of the hardcore. I've now started to backfill with that soil and I will add compost to finish.
When it's done I would imagine that the depth will be about 8-12", 20-30cm.
I know some plants such as violas and aquilegia will be fine but I would like to hear what flowering plants you all think would be successful in these conditions, including small shrubs.
The border gets full sun for an hour or two in the morning and most of the afternoon.
I had a similar problem with 20cm over a buried plastic pipe, didn't want anything too deep-rooting or that would pierce the pipe with a big strong taproot. Look for anything that likes a well-drained soil. Finding out which plants were shallow rooting was a bit of a nightmare as this info is rarely given in plant descriptions. I resorted to emptying plants from their pots in garden centres to have a nose...