Snappy Answers runs every Saturday afternoon. Send your questions, be they tough or trivial, to snappyanswers@torontoist.com. Spring is here, and I want to get started on building a garden on my third-storey deck. It's only 8-by-8 feet and faces south, so it has direct sunlight for, like, 20 hours a day. Last summer, everything I tried growing either burnt in the hot summer sun or was dug up by squirrels. Do you have any tips......