I’ve talked about this before, but it bears repeating — raised beds give you the Cadillac of vegetable gardens. Obviously, you can grow vegetables in the ground, or in containers, and they will do just fine. But raised beds offer so many advantages: the soil warms up and dries out faster than in the ground, enabling you to plant sooner. When the autumn rains come, the garden likewise stays a little drier than it would in the ground, enabling your garden to thrive longer in the season.
The soil structure is usually better in a raised bed as well – because you are not walking on it, the soil doesn’t suffer from compaction. This allows your plants to send roots down more deeply, enabling you to plant a little closer together than you would otherwise.
I am often asked about which material to use to construct a new raised bed. I advise against using pressure treated wood or railroad ties, as they leach toxic chemicals into the soil and could compromise your crop. We have built our new vegetable beds here at Farmington Gardens out of concrete building bricks, and they work great for that purpose – they are wide enough to also provide a place to sit while tending the garden. If you want an economical alternative to cedar boards, you can use fir and treat them yourself with this non-toxic wood preservative. I found this recipe last year, which is recommended by USDA to safely preserve wood for several years. I used it myself on my new beds at home – I mixed up the recipe and painted it on fir boards prior to building the beds. I must say I am a fan – they look great, the water beads up on them, so I have confidence they will last for a long time – the USDA claims they will last 20 years. I’ll keep you posted on that one!
Nontoxic Preservative for Untreated Wood
- 1 ounce paraffin wax
- 3 cups exterior varnish or 1.5 cups boiled l inseed oil
- Enough solvent (mineral spirits, paint thinner, or turpentine at room temp) to make a total volume of 1 full gallon
In a double boiler, melt paraffin. (Never heat paraffin over a direct flame!) Away from the heat, vigorously stir the solvent, then slowly pour in the melted paraffin. Add the varnish or linseed oil and continue to stir thoroughly. Apply by dipping the untreated lumber into the mixture for 3 minutes, or by applying a heavy coat. The wood can be painted when thoroughly dry, if you wish.