What I did was potting soil and compost mixed together for two beds. For another bed, I’m using dug up sod on the bottom (my soil isn’t bad, so I don’t mind if the roots grow down into it), mixed with some potting soil and compost. I haven’t planted in this yet, so no idea how it will do. The potting soil and compost mix is working well, but doens’t seem very frugal.

I think that mixing my own soil with some compost is going to be the most frugal thing, but maybe not the most fertile soil, at least for this season.

I had several reasons for “upsizing.” First, I wanted to grow some root vegetables, like carrots and potatoes. With my double-rail gardens, I had great success!

Second, I didn’t want to mow around my gardens, so I dug out the sod and covered the ground with weed mat, then gravel. the gravel gets REALLY hot, and I think the heat was stunting the growth.

Finally, I find that as the season progresses the Mel’s mix compacts down and sort of sinks. I wanted to be sure I had a MINIMUM of 6″ of soil–that was hard to do when the maximum that fit was 6″.

I just built garden boxes for a friend (watch for the post coming soon!) and used 2×10 boards. It was significantly cheaper than vinyl and I think 9-10″ of soil will work well for her.

You can use perlite instead of vermiculite. It’s not the same, but if cost or availability is an issue, use the perlite. I just built garden boxes for my friend, and we used perlite to keep the cost low. Use in the same proportions you would vermiculite.

Just a note–since my boxes are extra tall (12″ instead of 6″), I have modified my Mel’s mix to be 25% vermiculite, 25% peat moss, and 50% compost. I find it’s enough vermiculite and peat to retain water and make the mix light and friable, but it keeps the cost down.

Thanks.

Thanks for sharing your experience!

Be extremely careful when adding peat into Utah soil, that is clay.

Peat is extremely fine. It will bind with the clay and cause it to become harder. Which is exactly what you don’t want.
Also, don’t mix sand* into clay soil. When the summer heat comes, you will have turned your garden soil into adobe.

The best thing to do is add compost & lots of it. Avoid manures because of the salts.

*Sand actually can be mixed with the clay. Clay really holds water and is quite good with nutrients but they get locked up and the clay, as you know gets very hard in the summer. Sand is great to break up clay, but you will have to use more sand that you can imagine. A mix of 10:1 by volume is not out of the question. So for every pot of garden soil, if you mix in 10 pots of sand, it will make the clay friable. If you want to do that much work, okay, other wise, if you have clay soil, stay away from both peat and sand, as soil amendments.