The herb spiral is a permaculture gardening method that uses nature to its full potential. Gravity allows the water to seep through the levels meaning that the plants at the top get full drainage while the ones at the bottom may reside in a simple bog. It also gives your herbs shady spots with varying degrees. The herbs that need full-sun can be grown in those positions while more shade loving plants can be located on the opposite side.
Gravel can be used in dry streams, under downspouts, under decks, in between cracks on patios, and in streams or water features. Gravel comes in a variety of sizes from pea sized to oversized at 3in to 6in per stone. Colors range from buff to rusty browns.