Soil blocks for propagation
I’ve been experimenting with soil blocks this year. I’m not sure it’s right for us but I will give it a go with a backup of more traditional methods in case it all goes pear-shaped.
I make the 2 cm blocks using a Ladbrooke Soil Blocker, it produces 20 blocks which nestle in a takeaway food tray (these will be reused for years). The seeds are laid on top of the block, in a small dimple. So they are visible as they geminate. This is fascinating. Each part of germination plays out in full view. Most seeds germinate more quickly than expected - often within a day or two.
Small seeds do well but larger seeds don’t have enough space to develop in the smallest (2cm) blocks.
The whole process is labour intensive - specially at the beginning. Just enough water is added to the tray each day to keep the blocks moist but no sodden. I’ve found the weight of the tray is a good quick way to check when water is needed.
I keep the lid on the tray until 50% of the seeds have germinated, then remove the lid and place under full lights. The blocks then dry out more quickly and need checking twice a day.
Ammi Majus seeds after 1 week in their blocks.
Once the seedlings are about 2cm high I transfer them to 6cm blocks or a traditional pot. I feed with seaweed food after transplanting. Here are Stock seeds after 1 month under 12 hour high intensity light.
What I like most about using blocks is the immersive involvement in the germination process. It feels like an intensive care unit for seeds!