There are many great benefits to growing plants in raised beds. One of the largest benefits is the ability to harvest more produce from the same space. Raised bed gardens can actually double or even triple the amount of produce harvested from the space! This is due to the fact that the square footage needed for pathways is reduced considering, and and more space can be devoted to the plants.
Another great benefit to growing in raised beds is the fact that you can improve your soil conditions more readily, and you can even grow plants in areas with extremely inhospitable soil. If your garden is typically very sandy or you have a lot of clay, it can be difficult to grow much in it. But if you create a raised bed, you can simply put your own purchased or created soil mix into the frame and grow your plants in that.
Weeds are also much less of a problem in the typical raised bed. Because the soil is confined, it's much easier to spot any weeds that do pop up, and the weed seeds in the existing soil are buried under far too much soil to sprout in most cases.
The frames can also be built with a bottom and placed on tables so handicapped and older people can reach their plants to care for them more easily. This is a major benefit for people who otherwise would not be able to properly care for a garden.
This type of gardening was made popular by Mel Bartholomew in his book and television series called Square Foot Gardening. He developed a system that requires about 80% less space than traditional types of gardening.
Instead of being just a standard raised bed, the bed is divided into sections that house plants of various sizes. It uses special soil mix that is free of weeds and is ideal for growing almost any kind of plants. It uses less water, is all organic, and uses far fewer seeds than traditional gardening. His system claims you can produce 5 times more in the same space of a traditional garden.
The system divides each square foot into a grid, based on what type of plants you wish to grow in that section. If you want to grow a large plant like broccoli or cage, it would take one entire square foot, so that section would not be divided at all. If you want to grow rumors, you might section that square foot into sixteen separate spaces, each one housing a single holy!
Other similar systems have been bought out. Cubed Foot Gardening is very similar to Square Foot Gardening. The creator of this particular system is Christopher O. Bird, and he credits Mel Bartholomew for creating the original system. Bartholomew even cave the system an endorsement!
You do not have to use a grid system at all. You can use a raised bed to plant a wildflower garden or an herb garden with no definable organization. This works just fine. You do not have to restrict yourself to a grid-based system if you do not want to. Raised beds are very flexible!