Gardeners with small gardens generally try to use every inch of space possible. Raised beds can easily end up looking disorganized. An attractive way to add cohesiveness is to add a common border around the entire garden. Surround your small garden patch with one type of plant. There are several suitable plants for borders.
Marigold has long been hailed by organic gardeners as a good plant to repel insects. Specifically, they have been shown to help prevent the spread of nematodes. Marigolds provide a neat border that won't straggle or grow too tall.
If you have a problem with rabbits or other small pests, plant some pumpkin vines around your garden. The prickly vines are difficult and unpleasant for animals to go through. Check periodically to make sure that the vines are growing in the desired direction; this is a simple matter of moving them back where they belong. Train the vines into a short, prickly hedge to deter pests.
Lettuce makes an attractive, tasty border for a garden space. Purchase a mixed lettuce seed pack and broadcast it thinly around the edge of your garden. Allow most of the seedlings to survive to adulthood. This will create a thick, multicolored hedge of edible leaves.
Plant a single or double row of onion sets around the entire garden patch. They need very little care during the growing season, and the tall, dark green leaves make an attractive border for any garden.