Raised Garden Beds

Permanent Raised Gardens Without Preservatives

Raised bed gardening has seen a sharp increase in popularity as people turn to their own backyards to save money and eat more healthfully, but the construction of many raised beds can pose a problem. It is important to choose a construction material that is durable as well as safe for use around food bearing plants.

Landscaping timbers and other pressure treated wood products can leach chemicals into the soil, which can then be taken up into the edible parts of plants. Although the lumber industry has phased out the use of the arsenic-based treatment solution that has proven hazardous, there is no guarantee that the replacement will prove any safer over time.

Certain species of wood are known for their resistance to rot and insect damage, but even the hardiest wood will decay over time. In addition, redwood, cedar, and other durable outdoor woods are considerably more expensive than treated lumber.

Composite lumber is another long-lasting option, but is even more costly than cedar or redwood and as with treated lumber, there is the unknown of whether the plastic used to make it will be found to leach chemicals into the soil under the stresses of changing weather.

The solution to building truly permanent Raised Garden Beds that won't need to be resealed or replaced is as close as the foundation of your home. The same concrete block that is used in building can be used to frame garden beds with no risk of chemicals leaching into the soil and no problems with rot or insect damage over time.

To build a concrete block raised bed, first mark the boundaries of the bed with twine, chalk dust, or what ever happens to be handy. Level the ground along the intended outline, clearing an area at least 8" wide, and cut the vegetation within the area as close to the ground as possible.

Layering newspaper along the path can provide a simple, biodegradable way to kill grass and other vegetation under the block and the beds. It is better to use too much than too little, so plan on at least a dozen layers of newsprint to ensure heavy enough coverage to kill both lawn and weeds.

When the paper is laid, water lightly and start laying block. Fit the blocks snugly together, checking to ensure that they remain level as you work. Once the structure is finished, the bed can be filled with a mixture of compost and soil to prepare for planting.

When planning where to put your plants, don't forget about the openings in the block itself. You won't want to plant every opening; some should be filled with pea gravel or other small stones and left bare as a place to step when working the beds, but many of the openings can be filled with potting mix and used to plant decorative annuals or attractive herbs to surround your new vegetable bed.