Having permanent beds means you can permanently install structures such as trellises and fences, too. This allows you to build them for the long run out of durable materials such as pressure-treated pine, redwood, cypress or cedar. Raised beds have other strong points, too. Higher Yields Probably the most important reason for the raised-bed revival is more production per square foot of garden. A well-managed traditional garden may yield 0.6 pounds of vegetables per square foot.
Research shows that raised beds can more than double that yield.
Raised beds don't require the usual space between rows because you don't walk in the bed to cultivate or harvest. So you can plant vegetables closer. You can space them just far enough apart to avoid crowding but close enough to shade weeds. Avoiding Soil Compaction Soil compaction can cut yields in half. Water, air and roots all have a tough time moving through soil compressed by tractors, tillers or human feet.