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Edibles
Fertilizers, Pest Control and Soil Management

Raised Bed Garden Construction

Raised beds are one of the most efficient ways to garden in the Northwest. Raising beds allows for better drainage and allows soil to heat up faster and stay looser, which promotes rapid plant and root growth as well as easier weeding.

Raised beds can be achieved by simply mounding soil up to create a berm 4-6" taller than the surrounding pathways. A raised box, however, does have its advantages. One is that it makes it easier to turn your raised bed into a cold frame or cloche. Another is that by adjusting the height of your sides you can create a seat which can make working in the garden easier.

Design of the beds is easy. They should be slightly less than twice as wide as you can reach. For most people this is around four feet. 4'X8' beds use wood very efficiently. Sides should go 2" higher than your planned soil level (i.e. if you want a 4" raised bed, build out of 2X6's.) If you are planning a seat on your raised bed, a height of 18-20" is about right.

To construct the bed, first mark out the outside dimension on the ground. Remove the sod from the area and set aside. Cultivate the soil to a depth of 3-4" adding about 1/3 Cedar Grove Compost. A 4'X8' bed will take 6 Sky bags. For that size bed, throw in 1-2 cups of a complete organic fertilizer (Dr. Earth Starter or All-Purpose works well), 1 cup of garden lime, and rake in well pulling the soil into the center of the bed. Now set your frame into the hole then rake the soil back level. Replace the sod you removed GRASS SIDE DOWN in the box and then break it up into smaller pieces with a spade. Last, fill in the rest of the bed with a mix of half Sky Premium Planting Mix and half Cedar Grove Compost. (The 4'X8' bed will take about ½ yard of each.) Mix in 2-3 pounds of Dr. Earth organic fertilizer and 1 pound of garden lime. Rake smooth and water in, and the bed is ready to go.

To prepare an existing bed for planting, cut down and mix in (with a spade or digging fork) any cover crops about 2-3 weeks before you want to start planting. If you didn't use a cover crop last fall, knock down and rake off any winter weeds, add 1-2" of Cedar Grove Compost over the top of the bed (3 Sky bags for a 4'X8' bed) and lightly till in. Add 2-3 pounds of Dr. Earth organic fertilizer and 1 pound of garden lime. And plant!

And as always, don't hesitate to ask a Sky nursery person about your specific situation. Happy gardening!

Wood boxes are easy to make and require only basic carpentry skills. Pressure-treated wood should not be used for vegetable beds. Untreated cedar, fir, or hemlock will do just fine and should last 5-10 years or more in the garden. The boards should be a minimum of 2X6. This works well and is easy to handle. Most lumberyards will even cut boards to length if you don't feel like sawing. The only other thing you need is 3½" deck screws or 16 penny galvanized nails. The deck screws really work best. They can be driven with a cordless drill and will hold better over time. Joints are simple to make. Overlap the boards and drive the screws or nails in. If you are stacking boards up to make a taller bed, alternate the joint direction on each layer and use a 2X4 nailed or screwed on the outside of each corner to keep things aligned. Cut 1" PVC pipe to a length equal to the height of your box. Fashion 4 to each of the long sides using 1" pipe straps and screws. You can now easily bend ½" PVC into hoops to support plastic, row cover, or shade cloth, as necessary.

An alternative is to use stacking joints from Frame It All™. These recycled plastic joints are sized for 2X6 lumber, and are flexible, allowing you to make your bed almost any size or shape. Frame It All even makes 4' X 4' kits, available at Sky.

By Charlie Shull, WCN
Skylights Spring 2010, Vol 25, No. 1

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