Growing crops in raised beds has a number of advantages compared with cultivating open ground. In a raised bed you are able to control the soil mix exactly how you want and it is easier to prevent weed problems. Raised beds can be constructed from materials ranging from old wooden pallets to straw bales. Hugelkulture can best be described as a mound formed by covering a pile of logs with soil. To learn why this is a good idea read the following article which I found on the Backyard Gardening blog.
There is this old German fairy tale where a pair of spoiled children take their parent?s hard work for granted, not appreciating what is provided for them, until a monster known as the Hugelkultur attacks their cottage on night and eats their parents, leaving the children to survive on their own.
Just kidding. It is a German word, it means ?hill culture,? and in practice is a method of gardening where you bury wood and then plant on top of it.
Things like ?lasagna gardening? (where you build up a raised bed by alternating layers of compost, twigs & debris, newspaper and cardboard, and soil) are a variation on this, but true hugelkultur is pretty extreme, not just laying in sticks and twigs and garden debris with soil as you build a raise bed, hugelkultur could best be describes as covering up a firewood pile with soil, so you have a mound, or a swale, or a terrace. You put whole logs down, piling them on top of each other in a long triangular shape, then cover with soil. You have this sort of mound garden. Why do this at all? The wood both increases drainage and water retention, buried wood is capable of holding water like a sponge, it becomes a buried reservoir of water for your plants, and as it decomposes it increases organic matter and microbial activity in the soil and creates air pockets. It is also a decent method in any area where a raised bed is a good idea, namely areas where the ground is too rocky, the soil too shallow, or the soil just of too poor quality to do a proper garden bed. So rather than dig a bed into the ground, you build a bed on top of ground.
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Image source: Mark
IreneBo Adrian the original concept that I was talking about regarding those hybrid 3-sisters mounds.