The Field Guide to North American Truffles shows just 90 species of the many native truffles you may have to contend with. Only a few in the field guide are tasty. The rest are described as palatable, insipid, inedible or even poisonous.
And they will compete for space on the tree roots, especially if you don’t keep conditions in an optimal range for your cultivated truffles.
Declining Harvests in Europe
One mystery of the truffle trade in Europe is the falling size of annual harvests. Some put this down to loss of habitat from growing cities and expanding farms. Some think climate disruption is the problem. But no one has really been able to pin down an answer. I have a theory that could explain poor production in the wild and in cultivated plantings. I wonder if the lack of truffle productivity comes from their spores not being spread in the fashion they evolved with — being eaten by pigs and spread across the countryside.
My suspicion felt confirmed when a truffle farmer showed me a technique that has improved production on some farms. The technique is called Spanish Wells. Dig a hole at the edge a truffle tree’s drip line, and fill it with a wet mixture of spores and earthy soil mix. Come back to the spot in a year and harvest plenty of truffles that have attached where the roots were cut by the digging.
This sounds very similar to what would happen when a pig roots around for truffles: roots get cut, spores — in an ideal substrate — are deposited and new truffles get started. But I also wonder if turning loose some pigs at the ragged end of your harvest season — after you’ve already gathered nearly an entire season’s worth of truffles — wouldn’t bump up the next year’s harvest. Plus, just think of what you could charge for pigs that have chowed down on truffles before slaughter.
Frank Hyman is a former organic farmer who has a bachelor’s in horticulture and design from North Carolina State University. He also writes a column for Chickens magazine and is the author of the game-changing book Hentopia: Create Hassle-Free Habitat for Happy Chickens; 21 Projects.