Peat Moss v. Coco Coir.
In 2020 I wanted my first-ever seedling setup to be extremely neat + efficient. So I chose peat moss:
a “soilless” growing medium that comes from swamps + marshes. The decomposed moss effectively holds large quantities of water. (Of course that didn’t stop me from overwatering it at times.) On one hand this method of starting seeds worked well. The seeds didn’t take long to germinate, and I started hundreds of plants in a very small space.
The downside: gnats.
It took time and a lot of cinnamon – a lot of cinnamon – to get rid of them. It’s one of the few non-chemical treatments available, and It wasn’t fun. Although it smelled nice.
A less problematic (in the short term) issue was the effort in feeding the seedlings. They seemed to need a lot of nutrition, especially towards the end when there were a few surprise cold snaps preventing us from getting them in the ground for an additional 3 weeks. So there they were, these “giant” starts that needed food + more space than the little moss plugs provided. Fortunately the root systems were able to develop very well in this medium (the roots were many + clean + gorgeous). When they finally got into the ground they recovered quickly from being in too small a space.
And since they were not started in “soil”, they had to be treated like hydroponics. Liquid nutrients were applied and worked well enough. But anyone who has grown hydroponically can note how much extra care + caution is needed in growing this way. (The wrong amount of nutrients could either starve or burn the seedlings.) This solution wasn’t something we want to replicate in the future.
In 2021, we started seeds in coco coir.
No gnats!
The setup is messy.
I went for the ones that had the best reviews for quality: it’s crucial that the salt be completely washed clean from the growing medium. They are sold in these compact “bricks” which are great. But they must be mixed with water and allowed to expand; once that is done, that’s where the mess can come in. But this is really not a big issue, just a small issue for me personally (haha).
Anyway.
Coco coir holds water well too. Not as long as peat moss, especially when there’s a heat mat involved. But it’s enough. I also liked being able to quickly mix in the essential minerals right at the onset. Although this is technically a hydroponic setup too: in my opinion the coir allows for simpler setup + maintenance than peat moss as there are more options for providing nutrition to the plant.
Coco coir provides an amazing amount of aeration so that means less inputs for a “starting mix”… This is something we can get used to.
I started the seeds in larger single-cell containers this year instead of connected cell trays. So far this decision is one I’m pleased with (as of end of April 2021). I don’t really want to move them from cells to larger containers as some do. I just don’t want to. So I started out with the final size container I needed for the plant before it lands in its summer growing space. However…
I have to question the sustainability of this medium:
I am questioning the future availability of it as small-scale farming grows even more in popularity. We could I suppose buy enough to last a few seasons of seed starting. But is this a long term method?