"Raised-bed gardening is the easiest way to grow flowers and vegetables. Instead of planting in the hard ground, you garden on top of the ground. Build a frame from wood or resin boards, and fill it with easy-to-plant, highly-nutritious soil. Raised-bed gardens allow you to plant intensively, require less weeding and watering"
This from a leading home improvement stores garden newsletter.
You garden on top of the ground: Wrong. Unless your bed is taller than 30 inches you are still gardening IN THE GROUND. Most raised beds are about a foot tall. This means that many plant roots are still finding their way INTO the ground beneath the bed. A raised bed filled with gorgeous fluffy soil that sits on chunky hard clay is a waste of money. Any raised bed needs to incorporate the existing soil to be successful. This simply means mixing to a depth of 6 to 8 inches, the gorgeous fluffy soil , with the poor soil. No doing so will result in your gorgeous fluffy soil floating away in the next round of heavy rain.
Allow you to plant intensively: Plants have no idea if they are being planted too close together in ground or on the ground. Fact is intensive planting, aka square foot gardening, results too often in overcrowding, drought starved plants.
Require less weeding: Ever see weeds grow in compost! They don't grow, they explode, just like tomatoes do in rich composty soil. Raised beds are not a deterrent to weeds. In fact raised beds often require more weeding earlier and later in the season because the sun warms raised beds before flat ground and keeps them warmer in the fall.
Less watering: Let's see now, warmer soil, nutrient rich soil and intensive planting. Since when does that mean less watering? There are steps you can take to reduce watering in any garden: Mulching, compost, soaker hoses, drip irrigation etc, but just because you have a raised bed does not reduce watering needs. In fact it increases the need for water.
I use raised beds because of back problems and soil problems. They do make gardening easier but not fool proof. Harvesting is easier. The growing season is up to 8 weeks longer when raised beds are combined with row covers or clear plastic. Those 8 extra weeks alone can mean more water use.
So there you have it. Urban Legends have invaded the garden world. It should not come as a surprise though. This home improvement center feels the need to hire outside bloggers to fill their garden content needs. What would you say if your local independent garden center hired outsiders to dispense vital information on tomatoes? Most horticulturists are not journalists as I am and may need to hire someone to put their thoughts and advice into words. That is ok. But to outsource the entire information flow on a subject you say you are an expert in?
Stick to lumber..............................