Mushroom cultivation is cheap as it requires little space and simple structures. For instance 1 kg of spawn from the museum is Sh600 and would be enough for approximately 40 bags. Each bag would yield between two kilos to 2.5kg of mushrooms.PHOTO: COURTESY

Mushroom farming has huge prospects, but more farmers are yet to take it up as a commercial venture due to various reasons.

But there is tangible interest in mushroom farming evidenced by numerous inquiries on the Smart Harvest email and on various farming social media platforms. On that note, today, an expert and a veteran mushroom farmer will address all things mushrooms.

Susan Kabacia is a researcher specialising in mushroom production at the National Museums of Kenya. Here, together with her team they collect, identify, preserve, conserve and present wild mushroom species. Catherine Kamiri, a former accountant quit her job years back to focus on agribusiness and now she runs a thriving mushroom business.

1.Is it really a crop?

A mushroom is a fungi, usually usually classified differently from plants and animals. Mushrooms contain no chlorophyll thus they obtain their nutrition from breaking non- living organic matter or dead material in their surroundings. They are in the same class as yeasts and molds. Not all mushrooms are edible, as some have substances that are poisonous to humans.

2. Structure

The most appropriate and cost-effective structure for mushroom production is grass-thatched mud house. An 8 by 10 feet structure is enough to grow mushrooms. Ms Kamiri started with a 5 by 8 ft chicken coop, which she renovated and made into a mushroom house.

Ensure that the house is rodent-proof to keep off rats. It also has to be initially dark before introducing some light later on. Mushrooms, which have 80 to 90 per cent water content, need a humid environment to thrive. To achieve that, sprinkle water in the room throughout the day.

3. Materials

To start off, you need the spawn, which is basically the mushroom ‘seed’. Domesticated mushrooms are not grown in soil but in a substrate, which is what you mix the spawn with. Substrate is made up of agricultural waste. Almost anything that is cultivated on land is a potential substrate for mushroom cultivation.

You can use wheat straw, rice, banana and coconut waste, maize cobs, sawdust and even water hyacinth. Anything from the legume family, such as bean waste, is also great because of the nitrogen content.

You need bags for placing the substrate and spawn in to sprout the mushrooms. Polythene bags with a 2kg capacity are ideal. Ms Kamiri gets her spawn from the museum.

4. Cost


Mushroom cultivation is cheap as it requires little space and simple structures. For instance 1 kg of spawn from the museum is Sh600 and would be enough for approximately 40 bags. Each bag would yield between two kilos to 2.5kg of mushrooms.

5. Process

Shred the agricultural waste into small pieces and soak it in water overnight or for two days. After wetting it, mix it with supplements like wheat bran or maize bran. Next pasteurise the substrate by placing it over constant heat for six hours.

Pasteurising kills micro-organisms like bacteria, because mushroom is a decomposer and you do not want anything else grow other than your edible fungi as this would destroy the crop.

When the substrate has cooled, inoculate, which is introducing spawn by mixing it with the substrate inside the bags.

Take the bags to the house, place them on the shelves and incubate them for two weeks without touching them.

During these two weeks, the substrate will be colonising, until it turns completely white. When that happens, make small holes around the bags so that the mushrooms can start sprouting. Introduce a bit of light after making the holes.Ensure the room is humid by sprinkling water throughout the day. Temperatures should also be between 18 to 21 degrees.

Kamiri says she takes care of this by keeping clay pots filled with water inside the house. You can use a thermometer to ensure temperatures are right.

6. Hygiene

Mushrooms thrive on hygiene. Kabacia advises farmers to be careful when pasteurising. To achieve that, a farmer should ensure their hands are sterile when inoculating the spawn. Also ensure that the house is pest-proof. It is worth noting that if one bag is contaminated, it will spread to all the other bags and that crop will be lost.

7. Yield and benefits

It takes two months to get a mushroom harvest. A kilo of spawn is enough for 40 bags and each bag ideally produces 2 to 2.5 kg of mushrooms. A kilo of mushrooms fetches about Sh400. Kamiri sells hers in packets of 250g, each going for Sh150.

8. The market

Before you start commercial mushroom production, Kabacia and Kamiri advise that you establish a ready market however small.

9. Challenges

One of the things that can eat into your profits is firewood for pasteurisation, which is costly. Also, if you do not pasteurise properly, the fungi develops mould and that’s a loss. Given that mushrooms are perishable, they need to be sold immediately after harvest. Though they can be refrigerated for up to six days, customers do not like their taste.

10. Precautions

Do not pick wild mushrooms because they can be poisonous. And always buy your spawn from reliable sources such as the National Museums of Kenya, government institutions and universities like JKUAT. There are many instances where farmers have ended up buying low quality spawn, which leads to disastrous harvests.