Raised Beds

Raised beds minimize bending, are ideal for landscapes with poor soil (they’re a life-saver for desert gardening), and add verticle interest. These beds provide better drainage, warm faster in spring to allow earlier planting, and offer more control over soil type than flat planting beds.

Planning a raised bed

Before choosing building material, measure the area where you plan to build. When plannnig length and width, make sure you’ll be able to reach the center. A width or length of 4 feet (1.2 m) is reachable for almost anyone. Shorter garden beds also prevent soil compaction and allow more space in the area for wheelbarrows and other equipment. An added benefit if you're in the US is that timber is usually sold in a 4-foot length, as well. Take into account the sizes of material (the individual bricks, stones, or timbers) you want to use, so you don't end up needing half a brick to finish a wall. Alternatively, placing a statue or other centerpeice with a wide base in the middle of the bed will nearly eliminate the need to tend the center.

The height of the beds depends on your plans for them. In most cases a single layer of material is enough. If you’re goal is to reduce bending, the walls should be built to a height that’s comfortable for you—2 1/2 feet (.75 m) often works well. Most plants require at least 6-12 inches to root properly so if the bed is intended to provide something better than the local clay, sand, or gravel, the bed will require a height of at least ten inches, filled with rich topsoil.

Material
There are many inexpensive materials available to build the sides of a raised bed, primarily wood, stone, concrete, and plastics. If you plan to sit on the sides, go with a sturdy material that can be secured well.

Wood
Although any wood will eventually decay, it's a reasonably inexpensive material for the shorter term. If you choose wood, look for a naturally rot-resistant type like redwood, hemlock, cedar, or oak. Pre-formed landscaping logs, such as cherry stone timbers, are another option. A hole can be drilled through each ends, and re-bar inserted through the holes to hold the logs in place. Avoid railroad ties, however, which contain toxic preservatives that will leach into the soil (and just washing the ties won't get the chemicals out).

Brick and blocks
These provide a classic, finished look, offer more flexibility in choosing the shape and color of the bed walls, and endure well. They can be mortared together or held in place with re-bar.

Stone
Either purchased from a landscape rock yard or found free in your own backyard. For lower walls (under two feet) dry stacking the stones, using the dirt of the bed behind them to hold them in place, is enough. For higher walls, stones can be mortared together.

Plastic
For low price and low maintenance, plastic is the way to go. Plastic building panels and "timbers" come in a wide selection of styles and are nearly impervious to insect damage or rot.

Building the beds

Around the area of the bed, use a flat shovel to dig an edging ditch about 4 inches (10 cm) deep with a flat shovel and pile the dirt to one side to be used in the bed later. When the ditch is completed, slope the inside of your ditch to about 45 degrees, smoothing out the dirt as you work. Building the sides will depend on which material you've chosen.

Filling the beds

One of the prime advantages of raised garden beds is the chance to work with the best soil available. Fill your raised bed with a good mix of quality potting soil, mulch or compost, sand, vermiculite and a sprinkling of a dry fertilizer. If the soil in your area is healthy, include some of that, as well. Just make be sure that the soil is disease free. As you water, the soil level will settle and stabilize, so water thoroughly and let it rest a day or two before planting.

Unique raised garden bed ideas

Shaped raised garden beds
With flexible building matierial a raised bed can be circular, oval or even heart-shaped.

Double raised garden beds
This is simply a larger raised bed with a smaller one in the center. If the look is appealing, but you don’t want to deal with tending the middle bed, plant it wil a creeping ground cover that will trail down towards the lower bed. Because it’s closer to your nose, scented creepers such as creeping thyme or honeysuckle work well here.

Mini raised garden beds
A mini raised garden bed adds interest to nooks and corners without a lot of work and maintanence. Try a square bed on either side of your entryway steps, raised to the height of the steps, or even terraced at the level of each step. A small raised bed around the foot of a mailbox will add interest and give extra support to the mailbox post.

Hill-side raised beds
Building a terrace is one of the most effective solutions to a problematic hill. The beds are build to follow the natural form of the hill with the each bed out in front of the bed above it. Each bed will require three walls (front, left, and right). This structure will not only prevent erosion, but will add planting space to the garden. Find out more about how to landscape a slope >>

Temporary raised garden beds
An easier way to benefit from raised garden beds is a temporary version with no retaining wall. To create this, simply till the soil well to raise it above the level of the surrounding area, then add compost or potting soil to increase the height and add nutrients. Over the season these beds will erode back to the level of the surrounding area.