GARDENER'S READING ROOM
Edibles
Fertilizers, Pest Control and Soil Management

Raised Bed Garden Construction

Growing your own food is becoming more important to a lot of us for a host of reasons. Sustainability, a desire for organic food, and economics are at the top of the list. Plus growing and harvesting your own food is just plain satisfying and a great way to relieve many of life's stresses.

One of the challenges for vegetable gardening is finding the proper place to put one. Smaller yards, heavier soils, and our cooler maritime climate all present unique challenges for Puget Sound vegetable gardens. Raised beds provide a great solution for all these factors. They can be constructed in a variety of shapes and sizes to fit any size yard. Raised beds allow control of the soil type, letting you garden in fresh soil above our heavier clay soil, plus allowing the soil to heat up more in our cooler climate. They also can be easier to work. All in all, raised beds are by far one of the best ways to make gardens for food production.

Raised beds can be constructed from a variety of materials including concrete blocks, stacking wall units like cottage stones or Roman stackstones, recycled plasticboard, or recycled materials such as broken concrete or brick. The easiest, however, is probably simple wood construction.

Wood beds 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 item needed is 3 1⁄2" 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. An alternative is to use stacking joints from Frame It All™. These recycled plastic joints cost $13.97 for 2-packs, 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.

Speaking of size, beds should be somewhere between two and five feet wide. They can be wider, but to be really effective, whoever is working the bed should be able to reach the middle comfortably without stepping into the bed. Beds can be two feet long up to almost any practical length. However, any bed over six to eight feet long needs some sort of bracing (an interior sleeper or exterior post) every 4-6' to keep the sides from bowing. The Cadillac of beds would be 4'X8' and 18"-24" tall with a 2X6 cap nailed on top. This allows someone to reach to the middle and use the sides as a bench.

For soil, Sky recommends a mix of 1⁄2 Sky Premium Planting Mix and 1⁄2 Cedar Grove Compost. A 4'X8'X18" bed will require about 3⁄4 cubic yard of each. To this mixture add one 25# bag of Garden Pearls Calcium Carbonate and one 4# box of Dr. Earth All Purpose or Starter Fertilizer. This will make a great base for a vegetable garden. For best drainage, before filling the bed loosen the underlying soil about one foot deep, and mix that with the bottom layer of your mixed soil.

Sky has a great selection of products to make your vegetable garden a success. From seeds and propagation supplies to cover crops, organic fertilizers and pest control, Sky Nursery is the vegetable gardener's garden store.

By Charlie Shull, WCN
Skylights Spring 2009, Vol 24, No. 1

Other articles on edibles

Other articles on fertilizers, pest control and soil management