Growing Vegetables in Small Spaces
Back in the 1970’s the average backyard vegetable garden was about 1000 square feet. Now it is typically 200 square feet. New houses tend toward smaller yards, so the farm model of growing food and the generous space it required has become obsolete. Contemporary vegetable gardening borrows the best design ideas from the past, while incorporating new technology and materials to make smaller vegetable gardens easier to manage, and more productive. Two ways to coax more production from limited space is by borrowing from old cultures, the concepts of raised beds and vertical growing. Shifting a garden layout from rows to raised beds almost doubles the available growing area, as most of the ground formerly devoted to paths is dedicated to production. Growing food vertically to exploit the airspace above the garden again almost doubles its effective production area. This configuration facilitates the use of soaker hose irrigation, woven fabric mulches and other space age materials to dramatically reduce the amount of work involved in producing crops.
Raised beds are permanent, rectangular plots holding soil that remains loose and rich because it is never compacted by foot traffic. Paths between the beds are also permanent. While they require a significant investment of physical labor to dig and box, they do not have to be dug again every year. Raised beds promise years of virtually instant bed preparation and easy planting each spring. Try one bed at first. Dig it in the fall when the weather is cool, then add more beds over time. Because their excellent soil permits intensive planting, it will not be necessary to have as big a garden overall as before.
Making Raised Beds
Lay out the bed’s dimensions with stakes and string. A width of 3 or 4 feet is a comfortable reach from either side for most adults. Lengths of 8 or 12 feet (conveniently allowing for evenly spaced trellis supports every 4 feet) are most adaptable to the typical backyard. Begin digging within the string at one end, cultivating the soil to a depth of at least a foot--deeper is better. If working in a turf area, put aside pieces of sod for the compost pile. Working backward to avoid stepping on newly dug soil, turn over shovelfuls of soil and mound them in a loose pile within the measured dimensions of the bed. This is a good time to incorporate organic material such as compost, peat moss or chopped leaves into the soil.
Designate at least 3 feet for path area around the bed. Scrape off the valuable top few inches of topsoil from the paths and mound it on the newly dug bed to increase its height, then spread wood chips or gravel, or lay bricks in the path area to eliminate future problems with mud. Rake and level the surface of the mounded soil in the bed and it is ready for planting.
A layer of straw (not hay) or chopped leaves will protect the soil over the winter and discourage erosion of the mounded soil into the paths. While it is not necessary, boxing each bed with 2 by 10 inch wooden planks prevents erosion most effectively, makes beds easier to manage and looks more attractive. Boxed sides also provide a place to fasten fixtures to permit quick attachment of sturdy vertical supports for various crops.
When picking out wood for your raised beds make sure you are using untreated wood. Good choices for your raised bed would be cedar or hemlock or another wood that doesn’t rot quickly.
Reasons to Use Boxed Raised Beds:
- Save space
- Maintain soil texture
- Do not need annual digging
- Heat up earlier in the season
- Use water and fertilizer more efficiently
- Improve soil drainage
- Permit intensive planting
- Are neat and accessible
- Support trellises securely
- Permit use of shade cloth or plastic tents
- Avoids soil compaction due to foot traffic
The Value of Vertical
Another way to maximize production in limited space is to exploit the air space above the garden bed. Combined with raised boxed beds the potential for dramatically increased production with vertical growing is enormous. Plants grown vertically can be planted more closely together and produce more in the rich, friable soil of a properly managed raised bed. Because they take up only a few inches of surface soil, there remains lots of bed left to be intensively planted with low-growing vegetable plants. Orienting beds on a north-south axis assures that plant-laden trellises do not block the sun from lower growing plants as it moves from East to West across the yard during the day. Erecting vertical supports is always a time consuming problem. Free-standing ones provide flexibility in placement, but are precarious, tending to collapse part way through the season from the weight of maturing crops. The planks that enclose a raised bed offer a convenient place to attach year round fixtures that make setting up and taking down trellisesquick and easy. They make it possible to have a flat trellis system that runs along either side of the bed that is stable, yet easily reconfigured to facilitate crop rotation.
Establishing a Trellis System
There are lots of ways to fasten trellis poles to the wooden planks of boxed beds. One tried and true method is to fasten 12 inch lengths of PVC pipe, 1½ to 2 inches in diameter, with plumber’s brackets at four foot intervals along the insides of the long sides of the bed. Dig the PVC pipe into the soil so the opening is flush with the top of the board. Sturdy vertical poles, wooden or PVC, up to 8 feet long, fit easily and quickly into the PVC pipe fixtures for instant stability. Since their first 12 inches sit in the fixture below the soil level, the trellis will actually be 7 feet tall, about maximum reach for most adults.
Next you can cut 4 foot lengths (the distance between the vertical poles) of furring strips or similar 1 by 2 inch slats, to make crosspieces to make panels of trellis which fasten to the vertical poles at top and bottom. The trellis material itself may be hand-strung wire or twine, or commercial netting made of nylon or plastic. Mesh with 4 or 6 inch holes allows for easy access when picking large vegetables such as tomatoes. Fasten it to the crosspieces with a staple gun to form panels that are easily mounted and removed from the vertical poles, rolled up and stored for next year. Drill holes at the ends of the crosspieces and at the tops and bases of the poles for attaching panels of trellis netting with screw bolts and wing nuts.
Veggies That Grow Well Vertically:
- Beans, Lima Pole
- Beans, Pole
- Squash, Winter varieties such as acorn, butternut
- Tomatoes, indeterminate
Benefits to Vegetables of Vertical Growing:
- Better air circulation
- Better access to sunlight
- Less exposure to soil pathogens
- Easier to harvest
- Dry off faster after rain
- Less likely to be curled or deformed