These are the ratios I prefer. If you don’t need a huge batch you can use this as a basis for choosing a store-bought seed-starting mix. Always read the label and look for an ingredients list. Most popular brands have chemical fertilizers added that are unnecessary and will defeat the purpose of growing organically.
Instead, buy a basic mix and add in your own organic materials. I suggest adding a touch of vermicompost and watering your plants with a diluted sea-kelp mix. To be clear, seeds do not require any fertilizers until they produce their first set of “true leaves“. In basic terms this means the second set of leaves you will see. The first leaves that appear are called “seed leaves” and feed the seedling until the first “true leaves”appear.
- 1 part peat or coir (Coir is a sustainable peat substitute made from coconut husks. Peat is mined from marshland, destroying natural habitats. When you can, use coir.)
- 1 part perlite (popped volcanic ash that creates good drainage.)
- 1 part vermiculite (water absorbing material made from the mineral mica)