Portage River Farm

  (Pinckney, Michigan)
Notes on our struggles and successes on our family farm in rural Michigan.
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All Potting Soils Are Not Created Equal

Last year I was only growing food for our family. While it was all organically produced, the relatively small quantities of materials needed to start things indoors: lights, transplant flats and seed starting mix didn't warrant much more effort than running out to the local hardware store. Now that we have started a CSA, the much larger scale of our operation has me looking carefully at everything we are using to keep costs in line. That led me to turn my attention to potting soil.

At this time last year I was just getting started planting seeds in trays under lights in our basement. By the time spring rolled around, my little indoor garden had expanded to 16 flats on a couple of tables. This year is a completely different story. My planting plans call for more than 350 flats! Realizing that I was going to go broke buying the little bags of organic potting soil in the stores, I started researching alternatives.

It didn't take long for me to run across some excellent articles on making your own seeding mix. After reading up on the details, I picked a recipe that looked easy to do and began calling around to find out how much the materials were going to cost. I was imagining that I would buy bags of sphagnum moss, peat and vermiculite and just mix up batches in a 55-gallon drum. It seemed that I would save a bundle!

Unfortunately the folly of my thinking was soon clear. The pricing for the materials to make up batches of potting soil at home were adding up to rival the high prices charged for the bagged material at the store! There is obviously an economy of scale at work here and the only economical way to go would be to buy truckloads of each material and mix it up with heavy equipment. That would still have resulted in me spending a fortune and ending up with far more potting soil than I needed.

It was then that I recalled seeing a booth at the Michigan Family Farms Conference by a local family that runs a composting business. I looked up their number and gave them a call. The fellow who answered the phone, Justin, was knowledgeable and excited to talk to me. As it turns out, his family produces a wide range of products that start with rich composted dairy manure. To this they add a number of organic ingredients to produce custom blends for every application.

Unfortunately they are located a couple of hours away from our farm but Justin offered to meet us on the weekend when he was passing through a nearby town and bring us a few bags to try. I have now planted about thirty flats and I am very impressed. The soil is deep and rich, but the nicest thing about it is that it wets very easily and holds moisture far better than what I had been using. In comparison, the national brand might as well be made of ground up cork! I find that I have to water those trays every day since they dry out quickly and most of the water just drains out of the bottom.

On top of great performance, the potting soil is a fraction of the cost of the national brand. I also am very happy to be supporting a local family operation. The struggling Michigan economy certainly needs every dollar that can be retained in the state. I also have to assume that even though we will have to drive several hours each spring to stock up on potting soil, the carbon footprint still has to be considerably smaller than the truckloads of potting mix that are hauled all of the way across the country.

As you can see, our red, yellow and bunching onions are getting a very nice start. This weekend they will be joined by trays of celeriac and leeks. In another month we will have flats of green growing things crammed into every conceivable space awaiting the day when we can take them outside and finally start them growing in warm sunshine. As for me, I'm looking forward to taking a trip up to visit this new supplier and strengthen my connection to my local sustainable agricultural community.
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