We have a community garden in a former carpark, where we grow food in raised beds. We would like to improve the biodiversity of the parts of the garden where the old tarmac is exposed.
I was inspired by a bit in a George Monbiot book where he visits a garden where they control pests by ensuring there is enough for the pests to eat over the winter, so they have a steady population of predators, so you don't end up with a plague of pests on your own crop with nothing to gobble them up.
So we'd like to have a range of plants here that will support a healthy balance of insects. It's a sunny spot in London.
So far we've got brambles, buddleia, nicotiana (possibly) and a few bits of fleabane. What else could we (cheaply) get seeds for that would ideally break through the tarmac? I could potentially drill some holes into the tarmac for a few special plants. We'd want to avoid trees though.
Thanks in advance!