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:
- Sphagnum Peat Moss
- Mushroom Compost
- Vermiculite
Also recommended are organic sources of nutrients. Above you see:
- Blood Meal
- Bone Meal
- 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
Lowe's had these Bonnie tomato plants on sale 20 April. Besides being on sale, they were tomato varieties I wanted to plant. One thing about Bonnie plants I have learned over the last few years is that the variety you want may not be available if you wait to make your purchase later in the season. For those two reasons I purchased the following four tomato plants.
Each tomato plant got its own one foot square. I cut an X in the center of a square. I folded back each triangular flap to form a square. I then dug down to near the bottom of the raised bed, putting the displaced growing medium on the plastic mulch near the hole.
Using my thumbnail I removed branches about 6"/ 15cm up from the bottom of the stem. Why do this? Tomatoes sprout roots along the buried stem. The extra roots add support for the fruit. Plus, the tomato will access moisture deep in the soil that doesn't dry out as readily as soil near the surface.
Next I removed the label and pot from the growing medium and tomato roots.
If the roots are dense and growing in a circular pattern, 
they must be loosened, straightened, freed from that circular pattern. If you don't, the roots will continue to grow in that same circular pattern and not stretch out for support and access to more moisture.
Place the plant into the hole, roots first, of course. The bottom branches of the plant should not touch the plastic mulch when the plant is standing straight. If they do, remove those lower branches.
Return all of the displaced growing medium into the hole around the plant and firm it down a bit. Move on to the next plant and repeat. 
The four squares on the bottom row are each planted with four lettuce each. The two squares on the left side of the next row each has 16 carrots spaced equally.
