A fence makes a good line of reference.

The following procedure can be used to establish the boundaries and elevation of a large square or rectangular raised bed plot.

First, the site should have been adequately prepared and a grade established. Ideally, a surveying instrument was used to level the site or establish a uniform slope. If you have difficulty with this step, consult a soil conservation specialist, civil engineer, home builder, vocational/technical instructor or anyone with surveying skills.

Figure 1. Establishing a square plot

Initial squaring of plot can be accomplished with the aid of a framing square.

To do a good job laying out your plot, you will need the following tools: sledge hammer, carpenter's square, level, hammer, several small and large nails, twine or heavy string, two rebar stakes, eight wood stakes, a surveying instrument, measuring rod, two measuring tapes long enough to reach across the plot and a permanent marker. Begin by marking off one side of the plot. It is usually desirable to make this side parallel or perpendicular to the side of a nearby building, road or fence line. However, if the line of reference does not run true north-south or east-west, consider using a compass to establish the first side.

Drive two rebar stakes (points A and B) an equal distance from the line of reference or locate them based on compass headings (Figure 1). Make sure the distance between points A and B is greater by several feet than the actual plot measurement. String a line between points A and B.

When using a tape measure, make sure the tape is taut. Use the same tape for all measurements and be consistent in your technique. Although not required, the presence of a second person greatly simplifies and speeds up the measuring process.

Next, push a large nail (a 16-penny or gutter nail is best) into the soil directly under the string and at the point you designate to be one corner of the plot (point C in Figure 1). Place another nail directly beneath the string at the point designating an adjacent corner of the plot (point D). Line CD represents one side of the plot.

Measure the distance to both corners on the opposite side of the plot, designating their locations (points E and F) with nails. Use a framing square to make corners C and D as close to a 90-degree angle as possible.