Let’s talk about the soil we’re using in our seeding trays this year! We’ve waffled back and forth on our recommendations, so let’s talk about why.
For context, we’ve found it to be exceptionally important to offer our baby seedlings a relatively sterile environment for germination and the earliest stages of plant growth. Even a minor fungal infection or other biological competition can create severe problems for seedlings that are in their most vulnerable stages of life.
In the earliest days of our growing from seed efforts, we’d seek out specific “seed starting mix” as we could be relatively assured this was mostly biologically inactive and safe for our seedlings. However, this has become particularly difficult for us to acquire in recent years and so we had to mix it up.
So, we did some experimentations and started using our preferred potting soil several years ago, ProMix. We ultimately found ProMix to be of great quality and while it was not biologically inert, it just didn’t have the problems we’d encountered in year’s past from trying to use “regular” potting soil in our seed starting process.
Fast forward to last year and we suddenly had severe problems with sourcing ProMix. Ever the opportunists, we decided to give some of the cheapest, average potting soil a shot that would allow us to simulate the “average” gardener’s experience out there. Well, to say that (nearly) ended in disaster for our seedlings is an understatement. It didn’t even take a week until we had to fend off our first fungal invasion.
So, last year we leaned into our DIY efforts and crafted up our own seed starting mix using coco coir, perlite and vermiculite. We are still using this in our germination process this year, having made enough for a couple of seasons. We’re reasonably happy with it and if you’re curious about our process, you’ll find our last year’s post linked down in the comments.
Overall, the soil that you use in the germination process is an important decision. There isn’t “one” right product out there, but the focus does need to be on preventing (or at least severely reducing) biological competition for your seedlings. Your little babies that are trying their hardest to establish good roots will appreciate your decisions!
