Redwood is one of the best woods to use in any outdoor project, especially raised planter boxes or raised garden beds. Redwood is durable to the climatic elements and is naturally rot- and insect-resistant. To protect the planter box further, paint on a coat or two of exterior sealer, stain or paint, inside and out. If the planter is used for vegetables, make sure the material is organic, so it won't leach into your food.
Choose the location of your redwood raised long planter box. Mark off the area with the corner of your hoe. Dig up the ground dirt with your shovel, removing any debris (rocks, weeds, twigs) as you work the soil. Dig down a foot to 18 inches.
Rake the worked soil level.
Measure the area for the size of the raised long planter box, width and length.
Mark and cut two boards for the length of the box. Mark and cut two boards for the width of the box. The longer boards will be fashioned on the outside of the shorter, side boards. Make sure your side boards are cut 1½ inch less than the final width, to accommodate the thickness of the outside boards (each ¾ inch). For example, If the final width measurement is 8 inches, cut the side boards at 6½ inches.
Create a frame-shape with your cut redwood lumber. The front and back, longer boards should set parallel to each other. Place the side cut boards, crosswise, between the longer ones, at each end.
Use the drill and attachment to attach the four sides. Place a screw at the top and bottom of each end of the front and back boards. Drill them in so they catch the edges of the shorter boards.
Screw in an L-bracket or two, depending on the depth of your planter box, in the center of each inside corner. If you use two brackets, separate them by a few inches. The L-brackets will give the raised planter the strength necessary because of its length. Paint the planter box, if desired.
Place the completed redwood raised long planter box over the area where you worked the soil. Tap on the top of the planter box, with a hammer or mallet, until all sides are level.
Fill the long planter box with garden soil from the nursery or garden center, to 6 inches from the top. Layer on 2 inches of compost and mix it in thoroughly. Rake the mixed soil until it is even. The planter box is ready for planting.