I’ve grown all kinds of plants in various types of gardens, from rows and furrows to flat beds to modified
irrigated beds, but my favorite design by far is the raised bed because it’s a gardening control freak’s dream come true. “Leave nothing to chance” is my mantra, and although that goal is very difficult to achieve, a raised-bed marijuana system comes closer to it than any previous one I’ve used.
First, the soil here in the Southwest, is alkaline and often so packed that it forms a nearly
impenetrable deposit in the soil called caliche, which is a hardened deposit of calcium carbonate that has cemented all the soil particles together. I use the term “cement” accurately because caliche is used to make actual cement in west Texas. A raised bed marijuana garden allows you to avoid such excessive alkalinity because you can perfect the recipe for your own marijuana soil mix—just think of your raised bed as a very, very large container. And in the parts of the country where gophers are a problem, gopher wire at the bottom of the raised bed can keep the gophers from having their own pot party.
I built my raised bed marijuana system with four two-by-eight boards. I simply nailed the boards together and set them in the garden. Then I removed about four inches of garden soil from the bed to get it ready for the new soil. I don’t use any soil from my backyard in my recipe, although it will be there, a foot below the soil that I have created by using packaged “top soil” sold at big box home stores. Ingredients in these soils, which are sometimes labeled as “organic,” include composted plant and wood products (such as peat or sphagnum peat), lava sand and silt, sandy loam, gypsum, and sometimes urea to add a little nitrogen to the mix. The cost is reasonable, just a few dollars per cubic foot.
I completely fill my two raised marijuana beds, add my two-year-old compost until it’s about 20 percent of the entire mixture, and then I rototill it together and test the drainage by flooding the beds with the garden hose. If the water stands for more than thirty seconds (that’s never happened, but it could), I would add perlite in fairly large amounts. Most of the time the water drains completely in seconds, and that’s excellent drainage. More on http://www.ilovegrowingmarijuana.com/