Not only do raised bed gardens look incredibly tidy, they have brought style to vegetable gardens. Designers have matched the gardens’ walls to patios, as well as homes, greenhouses and barns. They have used raised beds as focal points in the landscape, and that includes mimicking a formal boxwood-framed parterre with raised bed gardens.
Finial-topped corner posts and path-spanning trellises aside, there are actually practical reasons to build raised bed gardens.
In cases where native soil is too sandy or clayey, where soil is contaminated or compacted and where drainage is poor, a raised garden is a sensible way to grow healthy vegetables and ornamentals.
A raised garden provides access for people who need to garden from a wheelchair or stool, and those who simply cannot bend to work at ground level.
Raised beds make useable growing space where the ground is covered with asphalt or cement. On slopes, raised beds can be formed into terraces for gardening.
Now that the practicality of raised bed gardening is apparent, don’t be too quick to succumb to a quick and easy raised-bed kit. Building a raised garden is a considerable project.
The endeavor starts with site selection. A vegetable garden needs ample direct summer s un— 8+ hours per day. Morning is preferable to afternoon sun. Set up the garden away from under the drip line of trees. Provide some wind protection. Make sure water is readily available.
Orient the garden north-south to prevent the taller plants from shading the shorter ones. East-west is the second choice.
The site needs to be prepared for a raised bed. That means weeds and grasses must be eliminated and the ground leveled.
The bottom of the raised garden can be lined with material like chicken wire, hardware cloth, landscape fabric or other barriers to protect against moles, voles and nematodes.
If you make the garden frame yourself, use rot-resistant wood like cedar, redwood or cypress. You can also use hardwood lumber preserved with linseed oil. Concrete block construction capped with wood (for sitting) is an option; so are stone, brick, corrugated metal and cor-ten steel. Recycled materials may (or may not) be less expensive than new wood or metal.
No matter what material you use, plan to do a lot of measuring, and expect to use your circular saw and power drill. Alternately, you can hire a contractor to build your raised bed.
Beds constructed with soil 18 or more inches deep typically require reinforcement to prevent the sides from bowing. Garden walls that will be used for sitting typically require fortification, too.
Research tells us that since 2003, pressure-treated lumber poses little risk that plants will absorb the chemicals used. If you are concerned, line your bed with heavy plastic sheeting or use untreated wood.
Consider 8 inches a minimum soil depth for your bed. However, most vegetables take the water and nutrients they need from the top 12 inches of soil. Therefore, 12 inches is a more beneficial soil depth. As with a ground level garden, the quality of soil is crucially important.
A general recipe for soil calls for 1 part compost or peat, 1 part sand or pearlite, and 2 parts good soil. Before you plant, have your new soil tested to find out what you need to add for best crop growth. Top your soil with organic mulch.
Count on irrigating your raised beds. A small garden can be hand-watered, however, drip irrigation is the efficient choice for raised beds.
Make pathways between raised beds wide enough to allow lawnmower, wheelbarrow or wheelchair access. Consider the surface of the pathway with regard to summer heat and ease of movement for a wheelchair or wheelbarrow.
Raised bed gardens require unnecessary labor and expense if your local soil is adequate. Consider also that the beds require extra water because the soil dries out quickly. It is your choice whether to install raised beds or not.
Build a raised bed garden as a design statement, but know before you start that the project is more demanding than a quick and easy kit. It is an undertaking that requires time, labor and money.