In a discussion I was having with someone about making compost from kitchen and garden waste, the question came up about whether we could use our own compost for growing our own mushrooms. I’ve always known that mushrooms will only grow when the conditions are exactly right and that they will grow if they have access to the rich range of nutrients that home produced compost provides.
So, can you grow your own mushrooms with the help of your own compost? The answer is yes, but you must ensure that the conditions are exactly right. There is a combination of circumstances that have to come together.
If you want to use your own compost for this, you must aim to make the best quality compost that you can. We have a post that will, hopefully, get you off to a good start. Go to Composting to find out more.
In nature, we often see mushrooms turn up in odd places where you wouldn’t necessarily expect to see them. It’s never immediately obvious why they turn up where they do, and don’t appear everywhere else.
If we want to cultivate mushrooms there are 4 basic measurements that have to collude together for any chance of a successful crop. These are:
- Soil moisture level
- Air moisture level
- Soil and air temperature level
- Soil nutrient level
All 4 of the above have to line up at the same time. If there is too much of one input or not enough of another, then, the conditions won’t be right enough and mushrooms won’t appear.
There are ready made ‘starter’ kits that you can buy. These contain everything that you need, as far as basic ingredients are needed. However there is much more to be understood as regards the required moisture and temperature level requirements.
For anyone who’s serious about attempting, what would essentially be, mushroom farming, there is a training-course, that I’ve found, that explains in detail, how to grow mushrooms. It consists of over 150 pages of instructions with illustrations and step-by-step instructional videos that cover most aspects of how to achieve the the right conditions for growing mushrooms.
You can find the course at: [ ‘Mushroom growing 4 you’ ]
This training-course tends to major on the main benefit of growing your own mushrooms being that home grown mushrooms won’t have been exposed to pesticides which, apparently, some commercially grown mushrooms are. If this is a concern to you, then, this is definitely a training-course for you.
What are the basics for growing mushrooms?
Mushrooms, to many, are something of an enigma. They are often viewed as a plant but they aren’t. They aren’t grown from seeds. They are grown from spores.
You need to have mushroom spores. There is a range of varieties out there to choose from. If you’re a beginner, it’s probably wise to start with something that’s relatively simple rather than diving in and attempting anything exotic.
You need to find a location that’s suitable for growing mushrooms. This is probably the most important consideration. They need to be in an area where there is sufficiency of everything that’s needed in terms of moisture and humidity. The ideal location is a basement-room that can be allowed to remain damp with a humid atmosphere. It must remain, mainly, constant although slight variations may be tolerated.
If you don’t have a suitable basement-room area or it’s not available for such use, it’s possible to grow mushrooms outside. The aim must be to achieve similar conditions to that of a damp, humid basement room.
This is possible to do. Using plastic sheeting, you can create a suitable microclimate that will retain sufficient moisture in the growing-bed and the air that sits immediately above it.
A more elaborate approach for anyone serious about growing mushrooms, perhaps commercially, would be to assemble a polytunnel.
A polytunnel designed for growing vegetables will be made from clear, transparent plastic, for obvious reasons. A similar construction can work for growing mushrooms but it wouldn’t need to be clear plastic. Black polyethylene sheet would be ideal. You would need to have two layers of sheeting to create an insulation gap.
One layer of black sheeting would absorb a lot of heat from the sun. This would make the interior of the tunnel too hot. Insulation would avoid this. Conversely, in cold weather, such insulation would be equally effective. Double-layer insulation would help to keep a constant temperature through the winter months.
An alternative approach would be to us plastic sheet that has been triple extruded for another application. There is a plastic sheet that’s available that has black on one side and white on the other. This would be ideal as the white side would reflecting heat from the sun thus maintaining a more suitable temperature in the tunnel.
A polytunnel will, probably, be too extreme for most people who just want to try growing mushrooms for the first time.
When you’ve settled on your location, large and ambitious or small for beginners, you have to prepare the growing beds. This is where you use the compost that you’ve made from all that kitchen or garden waste. Make sure that the compost is fully formed i.e. black and crumbly.
Make a layer of compost in a shallow container. A depth of 2 to 3 inches of compost should be enough. Then cover this with 1 to 2 inches of fine, workable top-soil. If you can’t get hold of top-soil you can use wood-shavings or sawdust. Don’t use anything with preservatives in it.
You then need to sterilize the top layer of, either, soil or wood-shavings to destroy any unwanted fungi or seeds that may try to germinate. The best way to do this is to pour boiling water over it. You may find it easier to place the soil or wood-shavings in a vessel and add the boiling water before spreading it over the compost.
The layer of soil or wood-shavings are known as the substrate, it’s where the mushrooms will be actually rooted. Some have suggested placing the substrate in a pressure cooker for a thorough sterilization. This would work for the wood-shavings but it will depend on how you feel about putting soil in a pressure cooker.
With the compost and sterilized substrate in place, we can load in the medium that contains your mushroom spores.
Keeping this moist is necessary but it doesn’t need to be soaking wet. Apply water using a mist-sprayer. You only need to keep the growing area damp.
Depending on the general conditions in your location, it may be necessary to cover the growing area with plastic to maintain constant humidity.
If all goes well, you should see signs of mushrooms appearing, around, three weeks after setting up the growing-bed. There should be harvestable mushrooms, about, a week after that.
What are the easiest mushrooms to grow?
For a beginner, it’s usually better to start with one of the most common types of mushroom.
For most, that will be the portobello mushroom. It’s technical name is Agaricus bisporus. It’s very safe to eat and can be harvested in the early stages of growth when it’s better known as the white-button mushroom. If allowed to reach full maturity, they open out into bigger, flat-topped mushrooms. At this stage they are referred to as portobello mushrooms.
Another mushroom that appears to be relatively easy to grow is the oyster mushroom. These are grown and consumed worldwide. They are known for their flavour and very expensive to buy. If you are looking for a mushroom that’s a bit more exotic, has a good flavour and you want to impress your friends with something that’s known to be expensive, then, growing oyster mushrooms could be for you.
Its natural growing habitat is on dead, rotting wood in forests where the humidity and light is low. The growing method, for home cultivation, will depend on which variety you want to grow.
The pink oyster mushroom is quite popular as it is faster growing. They can be grown indoors as they are a tropical variety and benefit from the warmth of a house. They can be grown indoors through the winter months as this is when the house heating is turned on.
In the wild they grow on dead wood but, to cultivate, they will grow on pasteurized straw. The spores are scattered onto the straw, after cooling from the heat treatment. Some oyster mushroom types do better in very low light while others perform better in some sunlight. Some varieties are temperature sensitive. It will depend on which variety that you choose.
When harvesting oyster mushrooms the trick is to twist them off at the base but leave some of the base as this will encourage regrowth.
How can I collect mushroom spores?
Some mushrooms are easier to collect spores from than others. The easiest, by far, is any mushrooms that have gills. This isn’t to say that you can’t collect spores from non gilled varieties, it just takes more perseverance.
Focusing on extracting spores from a gill-type mushroom, the process is quite simple. You need a mature mushroom that’s fully opened with the gills exposed. You place this, gill-side down on a piece of paper and place a glass bowl, upside down, over it. This is to stop it from drying out. Then just leave it overnight. You will then see the spores that have dropped out. These can then be placed in your growing area on the ready-made substrate.