Laying out your veggies in beds lets you cram more plants into a smaller area, producing more veggies in less space with fewer resources. That’s a claim that’s hard to beat! It’s no wonder that gardening books are touting the advantages of raised beds and “square foot gardening.”
The basic idea is that, instead of leaving empty space between rows, the plants are spaced the same distance in every direction. For example, instead of a linear foot of row (with a foot of space on either side) producing four carrots, you can harvest 32 carrots in the same amount of space!
Beds should be sized so that the gardener can reach into the middle without stepping on the soil. Mine are four feet across. They can be as long as is practical; mine are twelve feet. Standardizing my bed size allows me to build 4-foot-square hail screens, shade panels, and coldframe lids that fit anywhere in my garden. Having my beds be 4 x 12 (just shy of 50 square feet) also allows me to calculate fertilizer application rates easily.
These growing areas are separated by permanent paths. The actual beds are never stepped on, so the soil stays loose and easily penetrated by roots. Much less water, fertilizer, and amendments are needed because they’re concentrated where they will do some good instead of being wasted on non-productive soil.
Even better, the mature plants are arranged so their leaves just meet, creating a living mulch that shades the ground and greatly reduces the number of weeds. Mulching the space between growing plants keeps weeds down in the meantime.
In very arid climates, beds can be sunken below grade by a few inches, reducing evaporation. Here along the Front Range, where summer thunderstorms can bring torrential rainfall, raised beds have the advantage of draining rapidly. They also warm up earlier in the spring. If you have pets or small children, raised beds can help them see where it’s ok to walk. Raised beds can just be hoed into place (as shown here), or they can be contained by untreated wood or other building materials (as in the top photo). If I could start over, I’d probably use cinder blocks (spaced to allow some drainage), topped with plastic decking strips that I could sit on while weeding.
Since the beds remain in the same spot from year to year, it’s easy to add irrigation. We have plastic pipes buried along the ends of the beds. From them, risers deliver water to screw-on soaker hoses spaced about 12 inches apart (I have very sandy soil). A valve for each hose allows me to control water flow. I can turn it off completely if the bed is left fallow, or to dry garlic.
There are a few downsides to raised beds. The beds must be worked by hand; it’s impossible to use a large tiller in them. Even my lightweight mini-tiller is hard to control from the path, and it dumps dirt outside the bed. (Of course, since I never step on the soil, I hardly ever till it anymore.)
One extremely wet year, drainage became a major issue. The beds became bathtubs full of saturated mud. Water couldn’t drain into the compacted layer at the bottom. We’ve since added French drains, solving this problem. (Now we’re suffering from drought. It figures.)
Finally, as I mentioned last week, some crops just aren’t suited for growing in beds. Corn needs to be in blocks of at least 16 plants (and preferably more). Winter squash is much too big. It’s hard to hill up the dirt around potatoes grown in a bed. But this is an ideal way to grow root crops, greens, and bush beans.
In spite of these drawbacks, for most crops, beds allow you to grow more veggies in les space with less work and fewer resources. Clearly, gardening in beds is the way to grow.