Raised beds lend themselves to the development of complex agriculture systems that utilize many of the principles and methods of permaculture. They can be used effectively to control erosion and recycle and conserve water and nutrients by building them along contour lines on slopes.
Elevated garden beds are a good solution for plant drainage and compacting of the soil; plants will grow much better because of these facts. Raised beds will warm up faster in the springtime and continue to stay warm longer in the fall which means you can have a longer growing season.
A double skinned wall provides an air pocket of insulation that minimizes the temperature fluctuations and drying out of the soil in the garden bed. Sometimes raised bed gardens are covered with clear plastic to protect the crops from wind and strong rains.
For instance some companion plants for your tomatoes are onions, carrots, and parsley while cabbage and cauliflower need to be kept away. Be sure to rotate your vegetables every year, if you planted tomatoes in the green bed last year plant them into the red bed this year.