Railroad ties can be easily used to make a raised garden bed. At 8 1/2 feet long and 7 inches high, they can be cut in half to make the preferred 4-foot distance for an easy reach into the garden bed. They can be stacked in multiples of 7 inch increments, to allow for the necessary 6- to 12-inch rooting zone. Railroad ties are often found discarded or for sale at lawn-and-garden shops, and in many cases they may already be cut down to 4 feet.
Rough cut one railroad tie to 4 feet with a circular saw. Measure the distance with a tape measure, mark it off with a marker, and cut the tie at the mark. The ideal raised garden bed has a 4 foot width so that the plants in the middle can easily be reached. But that characteristic is solely dependent on the user and what they prefer.
Drill holes through each of the 8 1/2-foot ties every 4 feet, leaving approximately 6 to 8 inches at each end. One hole can be drilled into a side railroad tie at approximately the center point. A long, 8-inch drill bit will be needed to get through the 7-inch height of the railroad tie, but an 8-inch drill bit extension will attach to any drill bit. These can be found at virtually any hardware store.
Dig out a level 2-inch trench for the railroad ties to rest in. This will add stability and will allow you to vary the depth of the trench for level railroad tie placement. Use a level to check each tie, and dig out enough soil so that they are all even once laid down.
Stack the railroad ties so the holes line up. Ideally, alternate the stack on the ends so that on one level, the length of the laid tie goes all the way out to the end, and on another level, the width of the laid tie goes to the end.
Drive the re-bar through the holes with a mallet and into the ground to anchor the ties in place.