What’s so great about John Innes compost?

Early seed plantings

Early seed plantings (Photo credit: Tony Austin)

I like to listen to garden podcasts while I’m working in the garden (and, oddly, when I’m at the gym), and one of my favorites is Gardeners’ Question Time, from the BBC. Although it can be challenging to filter the discussions through the lens of my own, very different growing conditions, the program offers insights from extremely skilled and knowledgeable horticulturalists. I learn something new and interesting every time I listen.

One theme regularly recurs on the podcasts: recommendations of John Innes compost. Compost, in this context, refers to what American gardeners typically call potting soil. This compost is referred to with reverence by the gardening audience and the expert panelists alike, and seems to my foreign ears to be an underlying assumption of competent gardening in the UK. All your seedlings died? Well, did you use John Innes compost (you fool)? The question, in fact, precedes queries regarding basic care: “Did you water them? Did you expose the plants to light?”

This fascinates me. It appears from my research to be basic potting medium with set proportions of nutrients. But this cannot be the whole story. Clearly there must be something extraordinary about this compost, which doesn’t have an equivalent Stateside. There is no potting soil product in the US that inspires equal adoration. And to my knowledge, John Innes products are not available for sale in the US. I cannot discover the magic firsthand.

I admire UK gardeners’ devotion to organic methods and I wonder how John Innes relates to this. I know there are a few UK gardeners who read my blog. Please, demystify this issue for me! What is so magical about John Innes compost?

Homemade composter: Upcycled pickle barrel

I have never met a gardener who believed she had enough compost.

English: A picture of compost soil

English: A picture of compost soil (Photo credit: Wikipedia)

In the past, I have generated my compost in homemade bins made of 2x lumber and window screening, chicken wire, or whatever materials I had to hand. Those enclosures work well enough, but of course compost does take time.

I have always eyed those compost tumblers in gardening supply catalogues and wondered if they work as well as they allege. When I happened across a design for a homemade compost tumbler, from the blog Potholes and Pantyhose, I recognized a golden opportunity.

It was an especially fortuitous discovery because I happened to have most of the materials on hand.

Some years ago I obtained four pickle barrels off of Craigslist (about $15 apiece) with the intention of creating four rain barrels. I successfully made three. The fourth barrel had a lid that would not come off, no matter how we tried. It sat behind our shed until now, waiting for its opportunity to serve. I also had lumber and most of the necessary hardware, including a discarded metal closet rod that would serve beautifully as the tumbler axis.

homemade compost tumbler

The instructions at Potholes and Pantyhose are straightforward enough.  I found that the window latch hardware was insufficient to hold the lid closed, though, so I used a T-hasp closure instead (yes, that’s a stick stuck through the closure).

I’ve placed the tumbler next to my regular compost pile. Every time I go out to the pile, I give the tumbler a few spins (the kids also like to give it a whirl, which only accelerates the decomposition). Kitchen scraps, weeds, and newspaper go into the tumbler, while larger garden debris and shredded leaves and twigs go into the pile.

So far, it’s working brilliantly.