Quality seed deserves to be sown into a quality seed-raising mix. I’ve used bagged commercial mix and I’ve made my own – the latter producing the best results (see below for recipe). If choosing a commercial mix, look for something reasonably fine (free from big uncomposted chunks of bark, etc.), moisture retentive and airy, yet offering good contact with the seed. Certified organic options are very hard to find; we are not sure why.
A diverse range of containers is suitable for raising seedlings. Drainage is vital, so whatever you use must have holes in the base. Beyond that, it’s a case of finding a system that works for you. I’ve tried everything from used egg cartons to handmade paper pots to biodegradable peat pots to recycled plastic punnets, and it turns out that all containers have their advantages and disadvantages. Plastic punnets are convenient, water efficient and reusable, but they cause a greater level of transplant shock than biodegradable pots. The latter though will be dearer than homemade. An alternative is to avoid containers altogether. Soil blocks, which use a special potting mix and a ‘soil blocker’ mould to produce seedlings are a great option.
Make your own seed-raising mix
DIY seed-raising mix is cheap, easy to make and has the potential to be superior in quality to commercial bagged products. There are lots of recipes available, but my favourite goes like this: combine 2 parts compost (sieved to remove the larger chunks), 1 part vermiculite, 1 part coir (coconut fibre) and a sprinkle of blood and bone or worm castings to provide some nutrients.
An alternative favoured by Nick Ritar and Kirsten Bradley at Milkwood Permaculture is a mix made from 2 parts compost, 2 parts coir, 1 part worm castings, 1 part sand and a sprinkle of aged manure.
Then again, Phil Dudman, Organic Gardener’s former horticultural editor, swears by an even simpler mix of 2 parts compost, 1 part coir and a small amount of castings. Why not experiment until you find a mix that works well for you?
For more on raising seeds, including setting up a nursery and planting out, get your copy of Issue 97 Organic Gardener magazine OUT NOW.
By: Justin Russell
First published: September 2017