I use a mixture of peat free multi purpose (which I pass through a sieve to
breakdown the lumps) and my own compost plus some more soil from the veg
patch (again well sieved).
The multipurpose always seems to be too dry when used on its own so adding
my own soil and compost helps to retain some moisture.
The odd rogue seedling can be a problem but I can live with a tomato plant
in my hanging basket so long as it fruits (it did).

AndyP


"If more of us valued food and cheer and song above
hoarded gold, it would be a merrier world" JRR Toliken, The Hobbit