Raised Bed Growing Medium Recipe

Traditionally the growing medium for plants has been soil, dirt, earth, ground, loam or what ever you to call it in your neck of the woods. The composition and structure of soil can vary widely from place to place. To take the guess work out of the composition and structure of your local soil it may be better to create your own growing medium. Start from scratch. Play God a little bit.

According to the original Square Foot Gardening by Mel Bartholomew, the growing medium consists of: 

1. Sphagnum Peat Moss
2. Mushroom Compost
3. Vermiculite

Also recommended are organic sources of nutrients. Above you see:

1. Blood Meal
2. Bone Meal
3. Wood Ash for which I substituted Green Sand

In the photograph is enough peat, compost and vermiculite to fill two 4' x 4' x 1' / 1.2m x 1.2m x .3 m raised bed. That is 32cu ft/ .9cu m of material.

To start mixing the medium I dumped two bails of sphagnum peat moss onto the patio. The peat is very dry and light in weight. I then added three bags of mushroom compost to the pile. This bagged mushroom compost is almost wet and very heavy. Then it was time to mix the two together.

Using a square mouth shovel, slide the shovel under the close edge of the pile and place the shovelful atop the pile. Continue that action moving the pile away from you. The clumps of compost and peat will fall from the top of the pile and settle at the edge. Smash those clumps with the flat of the shovel to make small pieces of the large.

Be sure to move all the mixture in the pile and not leave any concentrations of components.

Once the medium is homogeneous add one bag of vermiculite. 

Using the same shoveling technique, mix the vermiculite until the medium is again homogeneous.

Add 1gal/ 3.78L of green sand and mix again.

The next step will take some time. Add water to the medium. Shower the pile with water. 

Both the peat and vermiculite will absorb a great amount of water. Use the same shoveling method as before to mix the water into the medium.

The medium will have enough water when squeezed 

it holds together in a clump. The mixing is finished.

It feels good to create.

©Damyon T. Verbo - all rights reserved