Quite obviously having a garden can save you a lot of cash but you can save a lot more if you can waste absolutely no space in your garden. Some people for example plant rows of vegetables but the spaces between the rows are wasted. Using space efficiently doesn't necessarily mean growing crops on virtually every inch in your garden. Between vegetable rows you can plant something like onions for example, vegetables which don't take too much space. How do the rest of you efficiently use up your garden space [and grow more vegetables]?
