Make Your Own Seed Starting Mix | DIY Gardening

Give your seedlings a headstart and make your own seed starting mix.

Your next bumper crop is right around the corner, waiting in a handful of seeds. If only all the seeds we planted grew past that awkward stage from youth to adolescence and into prosperous and fruitful adults. A bit of magic to guarantee success perhaps? Or just the right formula of sun, water, air, and a good seed starting mix?

Here are the basics:

• Start with the seed packet. It provides the optimal conditions for the variety at hand.
• Choose your growing location wisely. Sun is key but so too is a protected space.
• Water, it can be tricky to figure out, especially because the usual thinking is if a little is good then more is better. Not so with seeds. The soil needs to be damp but not waterlogged. Overwatering can be just as detrimental as too little water. See 8 Tips to Prevent Damping-Off of Seedlings for more ideas.
• Finally, soil. The general rule of thumb is to start seeds in light soil, nothing too rich or heavy in fertilizers. Seeds have everything they need inside them to get started, so choose a mix designed for planting or make your own, like I am here.

I’ve chucked plenty of seeds into an organic planting mix or straight into the garden with great success. But there are some seeds I treat with greater consideration. Either because I’m counting on them more, I can’t live without them and their growing season is so particular I don’t want to miss it, like tomatoes. Or because they tend to be more susceptible to issues such as damping-off, like lettuces. In that case, a soil-less mix does the trick.

But finding a soil-less mix without peat is a challenge. In fact, it can be nearly impossible. And the excavation of peat bogs, systems that take centuries to form with huge benefits to the environment, is something I can’t support. The stakes are too high. So, I don’t buy products containing peat. Coconut coir is a fabulous alternative and a natural byproduct of the coconut industry. Plus its pH neutral whereas peat is acidic, affecting the balance of your soil and the ability of plants to take in nutrients.

So, I make my own soil-less mix. The benefits far outweigh the time it takes to put it together which, as you can see, is only a matter of minutes. Not only can you make a peat-free product but you can craft it how you’d like, modifying the recipe as you would when cooking. Plus you can make the amount you need, not too much or too little, and it’s cost effective.

Soil-less Seed Starting Mix Recipe

• 8 parts hydrated coir
• 3 part worm castings
• 4 parts perlite

Hydrate coir in a container of water for 30 minutes. The brick will come apart and become flaky, like compost. Once it’s hydrated mix coir, worm castings, and perlite together. If it’s too clumpy and doesn’t crumble, add more perlite. Or vice versa, if it’s overly crumbly add more coir.

*Note: store-bought and homegrown worm castings can be quite different, which can also affect the consistency of your mix.

For tips on how to grow your garden from seed watch How to Grow Greens from Seed and for transplanting tricks watch How to Transplant Seedlings.

Other articles you might enjoy:

6 Solutions for Successful Container Gardening

Grow Your Own Herb Tea Garden

How to Grow Rosemary From Cuttings

This article was originally published in May of 2015.