Planting marigolds in your veggie garden can help repel pests. The smell from this flower in particular seems to mask the scent of the vegetables, keeping pests them from nibbling at your goods. This is a great, safe, natural way to keep your garden whole and organic.
Source: My wise gardener mother :)
Marigold flowers have many effective natural pesticides that can be beneficial around your garden. This is a page about using marigolds to control bugs on your tomato plants.