Most herbs have shallow root systems, which allow them to grow well in containers and raised bed garden planters. You can build an herb planter to fit any size of available gardening space. Smaller herb planters may be moved indoors during the winter so that the herbs may continue to thrive. Place garden planters containing herbs for culinary, medicinal or aromatic uses in locations that receive at least six hours of sunlight each day.
Measure, mark and cut each landscape timber into one 6-foot long section and one 2-foot long section. Each landscape timber is 4-inches wide, 4-inches deep and 8 feet long. To build an herb garden planter that will hold herbs with the deepest root systems, such as fennel and dill, the overall depth should be 12 inches. Three stacked landscape timbers will achieve this height. Adjust the length and width of your herb garden planter by adjusting the cut lengths of the timbers.
Stack two 6-foot long timbers; make sure that the ends are flush. Measure and mark the top timber at the center point, 3 inches and 15 inches from each end. Hammer a 6-inch pole barn nail through each mark to connect the two timbers.
Stack a third 6-foot long timber on top of the stack of two; make sure that the ends are flush. Measure and mark the top timber 2, 10 and 18 inches from each end. Insert pole barn nails through the top timber to connect it to the stack.
Repeat Steps 2 and 3 to make the other side of the herb garden planter.
Stack two 2-foot long landscape timbers. Make sure that the ends are flush. Measure and mark the top timber in the center and 4 inches from each end. Connect the two timbers with pole barn nails.
Stack another 2-foot long timber flush on top of the first two. Mark the top timber 3 and 7 inches from each end. Hammer pole barn nails through the marks.
Repeat Steps 5 and 6 to make the last side of the herb garden planter.
Join one 6-foot long side to a 2-foot long side at the ends in a 90 degree angle with 6-inch long pole barn nails. Insert one nail through the center of each landscape timber, 2-inches from the outside edge of the 6-foot long section. Repeat this step to join the remaining 6-foot long side to the remaining 2-foot long side.
Connect the two separate sections of the herb garden planter with pole barn nails the same way you connected the sides together.
Measure the outside dimensions of the base of the planter from one edge to the other. Measure, mark and cut a treated plywood board to fit the dimensions. The board can be 1/4- to 1/2-inch thick.
Attach the cut board to the base of the planter with 2-inch decking nails around the perimeter. Space the nails 4 inches apart.
Drill holes every 3 to 4 inches in the plywood base for drainage.