We used to spend hours making little newspaper pots with the Pot Maker for seedlings. It was fun the first time but real old after cranking out the thousandth pot with dried out newsprint stained fingers.
The soil cuber invention changed seedling time entirely for us. The concept is a little complex, but rock solid and easy once you have a system down.
It works like this – you have these metal forms that let you push out small, medium and large cubes of soil with. The smallest cubes are about a centimeter on each side and the largest are 2 inches. The small and medium cubes fit right into the next size up, nesting into them like russian dolls.
Unlike the newspaper pots which held the soil together, the cubes are compressed and contain the right ingredients to be structurally sound all by themselves. So you don’t have to worry about having biodegradable pots, there’s nothing to biodegrade!
The smallest cubes are for sprouting seeds, we talked about that in a recent article about germinating in the oven. The seedlings that actually germinate get transplanted into the next size up. The ones that don’t can be reformed into new cubes or reused.
We keep medium and small soil cubes in juice containers split in half. Since they’re designed to be waterproof the don’t leak all over the inside of the oven. Large cubers go in plant trays out in the unheated greenhouse to start hardening off.
We’re also working on a homemade set of soil cubers that can let you make soil cubes that will fill up a seedling tray perfectly. Once that design is done we’ll be able to share that as well. This is the soil cuber set we’re using right now, although the DIY design we publish this winter will hopefully be simple enough for anyone to make.
Next week I’ll share an easy soil mix recipe that works well with soil blockers.