Filling Raised Beds

🔥  "Which soil is best" is definitely a topic of hot conversation with gardeners.  This is what I did when I started building my garden because it was inexpensive and organic. 

I built my first raised bed in 2013 from some cedar fence boards.  Cost me about $30 then.  Easy to assemble, inexpensive, and fairly sturdy.  Looked pretty good, too! But I was surprised when it came time to fill the bed with soil - it cost me much more than the price of the bed materials!  Turns out -- good dirt ain't cheap!  

It is definitely worth looking for bulk soil if you can manage it.  I have seen 'garden mix' soils sold in bulk for $30-$50 a cubic yard (2023 price) if you can pick it up.  But I didn't have a truck to haul materials in bulk, and having it delivered was expensive and required me to buy much more than I needed. 

After looking at the options, I decided to mix my own "Mel's Mix", which is recommended in the book Square Foot Gardening.  It was a great book to use for reference when I was just starting out with my garden -- lots of good information and it simplified everything!  The recipe is at the bottom of this article.

• (If you don't want to mess with mixing your own, the least expensive bagged mix I have found is the Sam's Club brand 55-quart bags.  About $13 plus tax (2026).

Mel's Mix is a mixture of peat, compost, and vermiculite or perlite in roughly equal amounts.  (I know that peat is controversial now).  Since my bed was 4' x 8' and 11 inches deep, I needed 1 cubic yard of soil, and a big batch of Mel's Mix worked just fine.  AND best of all, my plants did really well in it.  In fact, I have used it as the basis for the growing media in all my raised beds since then, and it's been consistently good.

A few things to note:

• There is no "topsoil" in the mix.   Mel's mix is basically a potting mix, like what you would get in a bag for container plants, only without the chemical fertilizers. And it's pretty inexpensive for the large amount needed to fill a bed.  My beds are open to the ground at the bottom, so I don't have concerns about missing microbial life -- and worms seem to like it, too!  

• There might be some cheap compost options from your city.  Some cities (Bentonville, Fayetteville --that I know of) compost yard waste and sometimes food waste, and make it available to their citizens either free or low cost.  You need to call your city to see what might be available.  I have used Bentonville compost without any problems.

  • Be sure you know the origins of the compost you buy! Manure-based composts can be contaminated!  Read here about issues with persistent herbicides in manure-based composts -- it has become a real problem in home gardens ☹️ 

Each year, I refresh my beds by adding more compost, usually 4 inches or so that I work into the top of the bed.  This replaces the nutrients that were used up by the last batch of plants. 

If you have deep beds to fill, I have also used the Hugelkultur method to fill the bottom and then used Mel's Mix for the top 8-10 inches.  Saves a lot of money, and it works well with logs and leaves at the bottom.

And if I ever sell my house, I am taking my raised bed soil with me! It's an investment! 🏠