Thursday, 11 June 2015

Growing Mushrooms - Part 2

Growing Mushrooms - Part 2

Having read up a bit more I feel that my manure will have enough carbon and nitrogen and is only semi rotted / decomposed and therefore probably good enough for the mushrooms - if it isn't then I'll start from scratch with fresh manure, gypsum and straw as per instructions. If I do need to start from scratch then it will be only to see if I can get them to grow as it will be too much work to continue as a crop.

Hopefully, if I am right, then I now have a method of growing mushrooms in a repeatable manner with little fuss. 

The Mushroom spawn arrived, and I have mixed it with my compost. The compost is well wetted but not soaked.

In theory, as long as the temperature is around 20 to 26 deg C (30C and above will kill it lower than 20 will slow it) within a few days, perhaps 10 to 15 I should see the Spawn "running" through the compost like cobwebs. Growing outdoors means I'm at the mercy of nature for the temperature but as the spawn grows Carbon Dioxide is given off, which must be kept in the box, via a lid. The Carbon Dioxide encourages the growth. Depending on the temperature, humidity and carbon dioxide levels this stage could take weeks to months to finish.

Compost with the Spawn mixed in.
Each day, maybe several times a day, I'll need to make sure there is enough moisture in the compost but once the surface is full of cobweb like growth the next step can be made.

The next step is to encase the top of the mushroom compost with around 35mm of moss or normal garden compost (seed compost). CO2 (Carbon Dioxide) levels need to be reduced by removing the lid and letting in more air, and hopefully after a week or two there should be mushrooms.

One further problem seems to be that I may not have enough spawn for the size of the compost, but that won't matter too much as I will still be able to tell if the spawn is running and growing, if it is, but not enough to produce mushrooms I can simple add more spawn and wait again but this first attempt is mainly about seeing if my compost is right.

Fingers crossed.

Time taken to get to this stage:

30 mins for digging fire pit (re-usable)
30 mins creating box (re-usable)
10 mins digging earth for insulation (maybe more needed)
2 hrs moving manure and loading dustbin and emptying into mushroom box.
10 mins lighting fire and loading fire with wood.
10 mins mixing spawn.

Total: 3.5 hrs

I can see by the thermometer that as long as there is sun, even intermittent, then the temperature is about 20C, full sun doesn't raise the temperature much more (about 22C) so far but cloudy overcast conditions drop the temp to 15C or so. There seems to be little air flow and with the moisture I think that the humdidity will be OK and without air flow the CO2 should stay in the box to a large extent since it is heavier than air so in theory should just sit on top and within the manure as the fungi grows.

At this stage I'm fairly optimistic, especially as I have since read that the manure just needs to be partly rotted to well rotted and the Ph is 7.5 and looks OK. The manure isn't drying out as quick as I thought so that means less work. Just a shame that the next 3 days look a bit cool and cloudy but after that the forecast is for hotter weather.


  1. I thought it was spores rather thanspawn?

  2. Online definition

    Mushroom spawn:

    (Bot.) the mycelium, or primary filamentous growth, of the mushroom; also, cakes of earth and manure containing this growth, which are used for propagation of the mushroom.

    I think they grow the spores into mycelium. The mycelium is grown on sterilized wheat so that it can be transported. Either that or they put wheat into already growning mycelium to inoculate the wheat. I am at the stage of inoculating my substrate (manure / compost).

    Also found on a mushroom website:

    A substrate is inoculated with mycelium through the use of mushroom spawn. Spawn is just a smaller amount of a nutritious material upon which the mycelium can begin to grow before it's ready to colonize a substrate.

  3. Good luck with the mushrooms! Looks exciting.

    I've had lots of unidentified mushrooms growing from my compost once I've used it in the polytunnel.