How to win at making your own seed-raising mix on a market garden scale

The compost sifter was the first infrastructure we made on the farm!

We make all of our propagation mix and micro greens medium, using the sifter.

Key aspects of the design are short chains that are set back from the end of the screen frame. This makes the compost screen return easily when you are sifting
Below the screen is an angled plywood shute to collect sifted soil + compost into the wheelbarrow. We use a 6 mm woven stainless steel screen which creates a very fine medium and removes any debris.

We put 2 x 20lt buckets of home-made compost and 2 x 20 lt buckets of garden surface soil onto the screen before sifting. This is our generic mix for propagation and micro green production. Potting up long-season crops, such as tomatoes or cucumbers we can increase the percentage of compost for more fertility.

We use 30 m² of medium for micro greens annually which equates to $7000 if we had to purchase it.

The aerated medium creates fantastic soil-to-root contact, making transplanting a breeze.

It is easier to sift soil when it is dry. Once the soil is in the propagation house, we increase the moisture before tray filling.

The first setup I saw using a compost sifter was at John Jeavon’s farm in California.