My first job, after leaving college, was picking mushrooms, way back in the days when it was done by hand. The mushroom farm I worked at had a number of darkened polytunnels which were temperature controlled to provide the ideal growing conditions, all year round, for that diverse food so many of us love. Each of the polytunnels contained rows of black bags filled with compost. The mushrooms grow on the surface and are picked off every 4-5 days.

Mushroom compost is not something many of us will have come across. You most often find it for sale from mushroom producers, which is great if you live near one. Before I tell you what it is I will tell you what it is not. Mushroom compost is not compost made from waste mushrooms or parts of mushrooms, although mushrooms will compost very well.

Very simply mushroom compost is the stuff mushroom producers grow their mushrooms in. The compost is no different to any other commercially produced compost except that it will have been treated with the spores that grow into the mushrooms we eat. The bags of compost are stored in the dark and the mushrooms grow on the surface. When ready the larger mushrooms are picked off leaving the spores to produce more. Eventually the spores are exhaused and the compost no longer fit for use in this environment.

The used compost is a waste product from the mushroom farm but there are still plenty of nutrients within it and it is great stuff to use in your garden. The down side, or the up side depending upon your point of view, is that you will probably get mushrooms growing in your garden. They will be fine to pick and eat, so enjoy. If you fancy growing some mushrooms yourself and you don't live near a mushroom producer, you can buy mushroom growing kits from most garden centres. The kits contain compost treated with mushroom spores and the directions for a perfect growing environment. Once the growing season is over spread the compost you have around the garden and you'll probably get some more next season.  

If you have anything to add or just want to share your experiences with mushroom compost let me know.