Potting compost conundrum

With the Covid-19 lockdown I've found it difficult to get hold of sowing and potting compost. My pre-lockdown supplies have been used up. Because I mostly sow in modules and trays and then pot on rather than  sow direct I tend to get through a fair amount of compost. And of course now is peak time for propogation.

The garden centres and nurseries are all closed. The supermarkets I've have been to in recent weeks, on the odd occasion I have done a bit of shopping, are not selling it, or it is otherwise snapped up, perhaps by the same people who buy up all the flour. I quite often get compost from Lidl because it is cheap and also peat-free. I'm not sure if they had any, but there was a monumental queue to get in when I went by the other day and I couldn't bear the thought of more of my life slipping away if I joined it. It would also warrant thinking up some 'necessities' to buy which I had just purchased elsewhere. So for practical, moral and life affirming reasons, and needless to say, the health of the nation, I carried on home. 

Consequently I resolved to make my own potting compost. I have done so before but this time it was not a self-sufficient nicety but something that had become more or less essential. For the first time ever I welcomed the sight of some fresh mole hills - about 4 or 5. I scooped up enough to fill a wheelbarrow. Moles do an amazing job of sifting the topsoil to leave a neat heap with a nice, even crumb size. The next stop was my 'special reserve' compost made in the green composting bins. This is well rotted and weed seed free. I  sieved it to remove lumpy bits and to produce a finer texture and then mixed with some of the mole hill soil.

For the potting compost I used a 1-4 mix of molehill soil to compost. The important thing for potting compost is that it is both free-draining and at the same time is able to hold some mositure. Young seedlings or plants easily rot off if the compost is too wet and claggy. As soon as they have established themselves with a good root system they will be planted out.

For the sowing compost I used a 1-3 soil to compost mix. Sowing  compost does not need to be nutrient rich as most of the nutrients a germinating seed requires is in the seed itself. What is more important is for the sowing compost to be sufficiently fine-textured so that small seeds remain in close contact with the sowing medium. This is more readily achieved with a higher soil content. Once the seeds have geminated they can be pricked out or potted on to to a richer mix when the first true leaves are produced. I'll see how it goes and make adjustments if needed for future mixes.

I now have a supply of home made sowing and potting compost that will keep me going for a while. I am pleased with the results and my thoughts have already turned to next year and ways of escalating home production of potting compost significantly.

A sample of the home produced sieved compost mixed with
a bit of molehill soil for potting compost.