Think I've messed up ?

Hello all, good wishes to you.

Well, we've finally finished filling 2 large planters, (took 3 dumpy bags of topsoil, not far short of 3 tons, *by hand, in buckets!*)

I've mixed in some well rotted manure, and some general purpose compost to sort of "lighten" the soil (local soil tends to be a bit on the clay/heavy side) so in theory we are ready to plant.

BUT, I have ordered 2 Clematis, due to be delivered next week, and apparently they don't like manure! (Well, who does?)

So, what can I do to make sure my not cheap Clematis don't die?

Yours, concerned of North Devon.