By Michael Wardle, NSCF Adult Education Co-ordinator
One of the things when having your own garden is the ability to keep it going through sowing your own seeds. While some seeds benefit from a direct sow into the garden bed, many survive and thrive when they are planted in seedling trays first.
While you can spend a lot of money on seed raising mix, it is much easier and cheaper to be able to do it yourself. Typically, this can be done at home using things that we already have available to us and more so if you have your own compost and worm farm.
Below is a variant of a recipe I was introduced to years ago, which I use today. It is based on what I have in my local community that is readily available
3 parts sifted worm castings
2 parts copra
1 part river sand
First off, I sift my worm castings (vermicompost) so that they have an excellent tilth and remove any of the large chunks. While worms can have a simple diet and survive, to get the best vermicompost to use for seed raising mix or even in your garden, the more varied and diverse their diet the better.
I do not have a commercial sieve, but I built my own out of an old casement window frame and some fine chicken mesh. I tend to do batches of sieved vermicompost, so I have bins with lids to store it until it is needed.
Copra is the dried ground kernel of the coconut. You can purchase it at most produce stores. It is typically used to supplement the feed of animals, but due to its protein content it is also an excellent supplement for the microbes in the soil (which is fantastic for seed raising mix, which in turn ends up in our gardens). You can use coir instead of copra if you prefer.
I use river sand as it’s grains are large enough to help stop compacting in the mix and it allows the water to flow so that the seedlings do not become waterlogged.
Once the vermicompost is ready I use a large measuring cup and take 3 parts of worm castings, 2 parts copra and 1-part river sand and place them in a large bucket.
Mix well. Then mix well again. Then mix well again.
The idea is that each of the three ingredients is evenly distributed across the mix.
From there it is a simple step of filling the seedling trays, add the seed, and then I sieve a small amount of the seed raising mix on top to cover the seeds, then it all gets a good misting.
All that’s left to do is to care for the seedlings and plant them out when they are ready.
I have found this mix relatively inexpensive and has excellent results. So, start where you are, use what you have and get into it!