Starting Sweet Pea Seeds in Soil Blocks

Starting Sweet Pea Seeds in Soil Blocks

In the videos below I show you how to make soil blocks to start your sweet pea seeds in. Soil blocks are a plastic 'pot-less' way to start seeds off all kinds and sweet peas do very well in them. Soil blocks reduce transplant shock as the roots are 'air pruned' (when the root reaches the edge of the soil block it will continue to grow back into the soil block rather than along the wall of a pot).

To make soil blocks you will need:
~2” soil block maker (available here:
~cafeteria tray (12” x 16”) (available here:
~garden sieve (available here:
~peat moss
~compost (either home made or commercial)
~concrete mixing tub (or similar)
~Alaska Fish Fertilizer Concentrate 5-1-1 (available here:

Planting Mix Ratio

I use a mixture of peat moss and compost. The compost should be weed free and can be home made or commercial. I use 4:1 peat moss to compost e.g. 4 cups peat moss to 1 cup compost. I don't worry about adding anything else to the mixture because I will be giving my seedlings a weekly feed with fish emulsion.

Advantages of Soil Blocks

~Plastic free (apart from the cafeteria tray, however mine have lasted years and will last much longer than any other plastic plant trays)
~Make for easy transplanting as there is no pot to remove – simply pick up the soil block and plant!
~Cheaper (in the long run) than using plastic seed starting trays and pots which will break after a couple of years of use and will need to be replaced.  The soil block maker will last for years and years.


~Upfront expense: the soil block maker is a little spendy as are the cafeteria trays.
~Time: I have to spend time sieving and making the soil blocking mixture whereas a ready to go potting soil that I use in pots is ready to go.
~Watering: soil blocks are more exposed to the air and can dry out more quickly than pots so you need to monitor moisture levels more often.
~Using the soil block maker can make my hand ache a little if I am making a whole batch. There is a commercial blocker that make 12 blocks in one go, but it is way more of an investment and probably only worth the expense for commercial growers (



I love soil blocks because they are less wasteful and don't use plastic. My strategy is to continue to use all my plastic pots and starting trays but when they wear out and are no longer usable I don't plan to replace them instead I see myself using soil blocks more every year as I gradually phase out the use of plastic on my farm.


Sweet Pea Bouquet

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