Propagating Seeds with Soil Blockers
To get sufficient flowers for our customers and clients, we have to grow large numbers of all of our plants, making good propagation skills essential. We plant very closely, it cuts down on weeding and encourages the plants to grow tall straight flower stems. At roughly 9”/23cm spacing, a single 8m bed requires around 150 plants, so growing from seed is the best option for us. We simply couldn’t afford to buy in the number of plants that we need.
We grow our seedlings in small 15mm soil blocks created out of a wet mix of compost using an ingenious device called a Soil Blocker. They look like little chocolate brownies! 40 of these little blocks fit perfectly in a small plastic freezer container. Covered with a thin layer of vermiculite and with the lid on to prevent them from drying out, the seeds germinate really well. We grow these in our dedicated grow room. It was my studio but it now has three 8 x 4ft T5 grow lights which provide all the light and heat that the seedlings need to thrive. Taking the lids off, it’s easy to keep an eye on their needs. As the seedling’s roots reach the edge of the blocks, they ‘air prune’ themselves, creating many small fibrous roots within the soil block. They then transplant really well with very little root disturbance when we plant them outside, or bump them up into a larger 2”/50mm size soil block, created with a bigger soil blocker with a perfect indentation to pop in the seedling in it’s smaller soil block. 40 of these cubes fit into a readily available, reusable mushroom tray. These are brought on in cloches or low tunnels. It’s a brilliant system which the plants love and which saves us buying thousands of individual plastic plant pots or trays.
Last year we grew 5000 seedlings in this way in my studio, which changed function from a room where I paint and illustrate children’s books, to a room full of high tech lights, heat mats and germinating seeds. Having started their life in there, they are then moved to our polytunnel on the farm. This year a friend kindly salvaged an 8m polytunnel for us and it’s been a game changer, we just love it! It’s a lovely warm space to work on a windy, cold and rainy day, the sight and smell of all those young plants, shoots and sprouts always holds such promise. Tabitha loves poking about in there after school, seeing how her seedlings are growing and happily fiddling about. Helen and Murphy the lurcher love it too, as does Pete and Amanda’s splendid ginger cat, Leo. We just need a comfy sofa and a kettle in there...
Soil Blockers are available from soilblockers.co.uk
Originally published in December 2017 issue of the Sherborne Times.