Ask Alys: your gardening questions answered

My new ground-floor flat has a flower planter in a brick bed out the back. A couple of flowers are struggling out, but the soil is mixed with brick dust, dead ivy, fag butts, dead snails and sweet wrappers. I want a proper flower bed in this planter. Should I replace all the soil first? The cigarette butts and sweet wrappers need to come out, but the dead snails are an excellent source of calcium, so leave them in. Stamp on them to break them down first: coupled with the brick dust, they'll help to make excellent drainage (brick fines is added to some compost mixes for exactly that same reason). Given a little water, the ivy may even spring back into life. Chuck some new compost on top and it will either miraculously spring back into action or become compost itself. Buy the best peat-free potting compost you can afford. And mix in some well-rotted farmyard manure, too, to give the soil more body. I'd mix it all together and then save a little of the new stuff to top-dress the planter. Mulch with something decorative, such as bark or pebbles, because this will help conserve moisture. • Got a question for Alys? Email [email protected]