Truffle Farming

Meet Martha McCaroon. Find out how her passion for fungi foraging and the natural world has led to her working with trees and truffles after studying Woodland Management and Conservation.

By Martha McCarron · May 10, 2021

Hello, my name is Martha McCarron. I am 20 years old and am currently working on a truffle farm, based in Wiltshire. Since a young age I have been fascinated with the natural world because of the beauty there is in it. This passion led me to learning about Mycology. Myself and my Mum would go out foraging for mainly mushrooms. We would collect edible fungi and non-edible natural dyeing mushrooms. This fascination for the natural world around me, led me to pursuing an education in conserving it.

I joined an agricultural college in 2017, where I studied Woodland Management and Conservation. During my lunch breaks I would venture out into the woodlands surrounding the college, foraging for whatever fungi or herbs where in season. This led me to gaining the name Mushroom lady.

As a well-known foraging fanatic, I was approached by a lovely equine teacher called Becky. She invited me to do my work experience on the farm she kept her horses on. The estate had many business ventures, but the main project is truffle trees.

I have now worked on the estate for almost a year and can safely say it has solidified my love for fungi!

What are truffles?

Oak with black truffle mycelium at 4 years

A truffle is a fruiting body of a subterranean fungus which grows on the rooting system of trees. Known for their distinctive aroma and radiant taste, they are one of the most prized ingredients in cooking. They are also known for being very expensive.

Traditionally, to obtain the fungus, truffle hunters would go out to woodlands to find them. They would bring pigs to sniff out the scent of the truffle. These days truffle hunters use dogs as they can be trained and unlike the pigs, they won’t eat the truffles.

This time-consuming process of finding the truffles made them prized and valuable.  Truffles only have a very limited window of consumption (depending on type). Within 3-5 days the truffle will lose the majority of its potent scent and within 10 days the truffle will lose its taste and value.

Fungi cannot be regrown after being removed from the rest of the organism. This means that they cannot be preserved once picked. These factors combine to make it one of the most expensive culinary ingredients. 1kg of the most expensive truffles (alba) can be sold for £10,000.

On the farm we produce three different types of truffle, melanosporum (black truffle), uncinatum (brown summer truffle) and alba (white Italian).

How to grow truffles 

Oak with black truffle mycelium at 2 years

We start by collecting seeds from the estate or buying in seeds that correlate to the type of truffles needs. To ensure optimum chance of producing a truffle tree, we must take care in choosing the best seeds.

Next is the soil type. We use bagged soil because it ensures quality control. If there is a large amount of mycelium or bacteria in the soil, it could contaminate the truffle mycelium and the tree would grow but the truffles wouldn’t.

The soil is then mixed with a concentration of correlating truffle mycelium. Depending on the truffle more calcium is added to the soil too. Once the soil is mixed, we plant the seeds. As the trees grow, we transfer the trees to larger pots, each time inoculating the soil with mycelium.

It can take 2-5 years before transferring the tree into the ground as they need to be large enough to withstand the elements and have a high enough concentration of mycelium, so they won’t get contaminated by another mycelium. Throughout the growing process, the trees must be delicately looked after. We must ensure to remove any weeds that could be taking energy away from the tree or contaminating it with pests.

Once the trees are in the ground it can be another 7-10 years before harvest. When the trees reach the 10–12-year mark, a clear indicator that the symbiosis of the mycelium and the tree has worked is a white ring around the tree called a brûlé (burning).

On the estate we have been growing truffle trees for over 8 years and are hoping for our first harvest this year! When the truffles are ready for consumption, you can put your nose to the ground and smell the aroma of them. Last year we had a truffle hunter and his dog come and see our trees. The dog was able to smell the aroma and we found a few separate parts of a truffle but no fruitful harvest.

Truffles grow anywhere on the rooting system of the tree it is in symbiosis with. To preserve the trees, we only dig down to a maximum depth of 6 inches. This process called cavage, must be done with the upmost care, making sure not to damage any roots.

To conclude, truffles are delicate organism which take time, consideration and effort to create. To grow a tree inoculated with truffle mycelium is one thing but to make it fruit is another. Working with these trees has made me become patient and has been such a grounding experience in these turbulent times

Brown truffle mycelium on conifer at 6 years

Definition of words

Fruiting body: fungal structures that contain spores.

Subterrain: something that occurs under the earth’s surface. (truffle)

Symbiosis: Biological interaction between two organisms

Mycelium: vegetive part of the fungus

Inoculation: introducing a mushroom spawn into the soil