It holds dirt, it's cheap and total novices at woodworking can build it with just a saw and a large rock.

One reason I like this construction method, despite the ramshackle appearance, is that it is easy to modify or remove. If you are renting, or if you want a cheap, temporary bed while you decide whether you like gardening ... this would be ideal.

This bed has been through several revisions and expansions in its short life, and had several versions of frost protection.

Step 1: Design

The ideal raised bed is narrow enough that you can pull weeds and harvest vegetables without having to step in the bed and mash all that nice soil. For most people, if you can walk on both sides of the bed, a depth of 4 to 5 feet (120-150cm) is practical.

To increase the width of the bed without making it too wide to reach the center, I cut boards and made 2ft x 2ft (60cm x 60 cm) indents on one side for space to kneel and harvest or weed. (version A) It is not obvious from the photos, but there is a narrow path between the bed and the fence. The bed is about 6 feet x 18 feet (180xm x 550cm).

If your space is against a wall, the part closest to the wall should be about 2 feet (60cm) deep. You can make 'finger" extensions that are 4 feet wide to increase the growing area.

For maximum growing area, if you have a square garden area, use Version C.

Step 2: Tools and Materials

The boards will ideally be rot-resistant, but use whatever is available. Reclaimed pallet slats are OK, but they are short. You will need more stakes if you use short boards.

One or more bundles of 12-inch (30cm) construction marking stakes.
Cedar fence slats or other boards 3 or 4 inches (8-10 cm) wide, preferably 6 to 8 feet (180 to 240cm) long
A saw of some sort to cut boards with.
A hammer or mallet to pound stakes with. I was not joking about using a rock, but a mallet is easier to hit the stakes with.
Square-shaped plastic containers, such as small nursery pots or milk bottles to block the corners with.
Dirt and compost to fill the finished bed with.

Step 3: Construction

Construction is simple:

Pound stakes into the ground to hold the boards on edge. As shown in the first picture, 3 stakes hold each board or pair of boards upright. Use two stakes on one side and one stake in the middle of the opposite side.
A 12" stake can hold 2 fence slats. If you want a taller gardening bed, buy longer stakes and use wider boards.

If you are making the indents, cut 6 boards, each 2 feet (60cm) long, for each indent.
The corners butt together, with something to prevent dirt from seeping out of the gaps at the corners. I used some nursery containers cur into quarters, but milk bottlers or even chunks of wood can be used.
The boards on the long sides are overlapped and staked into place, as shown in the third picture.

Fill it with compost or dirt from your yard.

Step 4: The Inevitable Questions, and Answers

Q. Are the sides strong enough to hold all the dirt? They seem flimsy compared to what I see on the Internet.

A. Yes. The weight of the dirt is pushing down toward the ground, not outward against the walls.

Q. Are you really growing lettuce in January?

A. Yes. We have sunny weather most of the winter, with freezing nights and cool days, and only an occasional snow. The frost cloth holds in moisture and the cold-tolerant leafy greens thrive. Unfortunately, by the time the tomatoes and chili peppers are ripe, the lettuce has died from the heat.

Q. Is it difficult to remove the structure?

A. No. Pull the boards straight up, then pull the stakes out. The dirt can be raked flat, or shovelled into carts and moved.