I’m mostly a peat-free gardener: life’s too short and the world too precious to ruin a peat bog for beans and lettuces, and besides I kind of accidentally started peat-free (long before it became a hot topic in gardening) so I learned to garden without peat without even particularly knowing the environmental implications. You do treat peat-free composts differently: they’re more open, for one thing, so I’m used to watering my pot-grown seedlings a little more often. I had a go at growing stuff in a peat-based compost once, just to see if I was missing out on anything, and everything drowned.

But that word ‘mostly’ is in there for a reason. I’ve never been able to escape the use of peat in seed composts: I’m kind of fussy about what I start my seeds in, mainly because it can be the difference between modest success and abject failure, so I’ve always taken the safe course of action and plumped for John Innes seed compost blends. These are soil based – but they also have a proportion of peat. I’ve not been able to find out what proportion (compost makers are notoriously cagey about exactly what goes into their recipes) though some John Innes style mixes give it at one part sphagnum moss peat to two parts loam. Still too much for comfort as far as I’m concerned.

I had been turning a blind eye to this, reasoning (slightly uneasily) that since I don’t use as much seed compost as potting compost in an average year it was only a small proportion of the compost I get through. I’ve been stewing up a plan to make my own as an alternative, but haven’t quite got the leafmould together yet (one year done, one year left to do) and I never have enough garden compost.

And then I came across Carbon Gold. It’s got two very of-the-moment things in it: the first is mycorrhizal fungi, which is to say types of fungal organism which can form symbiotic relationships with roots, plugging them in to the soil around them so they access nutrients and moisture better. And the other is biochar: basically, charcoal.

Biochar comes in soil improver as well as seed composts; it acts like a sponge in soils, absorbing moisture and opening up the soil (rather like any kind of organic matter). And best of all, it acts like a carbon sink – so you’re doing your little tiny bit to help the environment by gardening, instead of carving it up.

I thought all this sounded rather wonderful: so I decided to try it out for myself and see if it really worked as a seed compost (the acid test: whatever it’s got in it, there’s no point in using a seed compost if your seeds don’t actually grow in it). And I (or rather the hubster) filmed the results: click play for the lowdown, courtesy of the crocus.co.uk Youtube channel.