by Karl H. Kazaks
HILLSBOROUGH, NC — A stroke of luck pushed Franklin Garland into truffle notoriety.
It was the early 1990s. Garland, at the time a commercial shiitake and oyster mushroom producer, was hosting a group of students from Duke University at his farm. Someone asked about the truffle orchard he had planted some dozen years before.
Garland had planted the orchard — inoculated European filberts (Corylus avellana), Holly oaks (Quercus ilex), and English oaks (Quercus robur) — in 1980 after becoming fascinated with the fungus the year before. He had read an article about a new method of inoculating trees for truffle production.
“I didn’t even know what truffles were at the time,” he said. But he set out to learn as much as he could — even travelling to southern France in 1979 during truffle season to taste the delicacy for the first time.
He came back from France determined to grow truffles on his own farm. But at the time of the Duke students’ visit he had never harvested a truffle from his own orchard. He didn’t even know if his orchard was producing truffles.
As it turned out, the Duke visit was during truffle season. Garland didn’t have a dog trained to hunt truffles, but he had a group of interested students. So he waved a $100 bill in the air, offering it as a reward to the first person who found a truffle in his orchard.
The group walked from the mushroom house to the orchard. Garland knelt down and brushed back some leaves — and, as he said, “I put my hand down on a truffle” — a black Périgord (Tuber melanosporum) protruding from the ground.
“It was like it was meant to be,” he recalled.
Soon Garland was on TV, and people were clamoring for him to help them raise truffles themselves. Garland quickly built a truffle tree nursery business — selling inoculated filberts and oaks to buyers interested in planting their own truffle orchard. By 1998 Garland had left the mushroom business to focus exclusively on the truffle tree nursery.
Truffle cultivation takes patience — and dedicated maintenance. It usually takes at least five or six years — and sometimes as much as 12 years — before a truffle orchard begins producing. And that’s using the intensive strategy Garland has developed.
The key to maximizing truffle production is maximizing root production — the host on which the truffle fungus symbiotically grows.
Garland’s first orchard counted 500 trees over three acres — too low of a density, in his opinion, to quickly reach optimal truffle production.
Today Garland recommends 500 trees per acre. (He plants trees six feet apart on twelve foot rows.) With that density — and proper management — a truffle orchard can produce 75 pounds per acre per year. At $800 or more per pound of truffle, that’s a lot of revenue.
There are a number of factors which affect production — including soil moisture and soil temperature — but where most would-be truffle growers come up short is in management.
Growing truffles, Garland said, “Is like growing tomatoes. You can’t just stick a plant out there, do nothing, and expect optimal production. You really have to dedicate yourself to them.”
In France, most truffles are produced on calcareous soils — soils with a pH of at least 7.6, and often between 7.9 and 8.3. It could be possible to grow truffles in soils with a pH in the low 7s, but either way, if you’re trying to grow truffles in naturally acidic soils it requires copious annual liming.
“In reality, high basic soils are detrimental to growth of the tree and fungus,” Garland said. But it is the stress from the basic soil conditions that causes the fungus to produce truffles.
So what Garland recommends for truffle production on acid soils is to get the soils above neutral during the first years the orchard is established, at a low basic level that will allow for optimal tree root and fungus growth. But when the root-fungus mat on the orchard floor gets large enough to start becoming capable of fruiting, he then switches to a higher-pH management.
But liming is the easy part of truffle orchard management. More intensive is the effort Garland makes to reducing competition in the orchard. The idea is that as the incidence of other species increases in the orchard, the growth rate of the tree roots slows. And the goal is to reach truffle production quickly.
Fruiting of truffles requires not only the stress of basic soil conditions, but also a completely developed root mass. If there is room for a tree’s root mass to continue expanding, the fungus will continue to grow along with the roots and not fruit. It is only when the soil is saturated with a soil-fungus mat that truffles will fruit.
“Once the fungus runs out of roots to colonize,” Garland said, “it runs into itself and starts to form primordial nodes,” from which truffles can emerge.
In a young truffle orchard, he helps reduce competition by using woven polypropylene mulch around newly planted saplings and by cultivating the soil six to eight times a year to eliminate weed pressure. He cultivates both with a tractor, and then with a hand-held tiller at the edge of the plastic. He even (with farm labor) touches up with a hoe as needed.
Once a truffle orchard reaches about five years of age, Garland will switch to cultivating only in the spring — a shallow, two-inch deep discing. By loosening the soil that way, it not only allows the fungus to fully develop through the season, possibly fruit, and make it easier for truffles to grow through the loosened soil, but it also acts as root pruning, encouraging the trees to continue to produce roots.
At that stage of maturity, a truffle orchard should have its own herbicidal quality — the presence of the fungus in the soil acts as a natural deterrent to plant growth. The pattern or area in which plant growth is suppressed is called the brûlée — French for “burnt” — because the lack of weed growth makes the area appear burnt.
The good news is that truffle orchards do not need to be fertilized. In fact, says Garland, doing so is “actually disadvantageous.” That’s because the fungus provides macronutrients to the tree like N, P, and K — that’s what it provides in the symbiotic relationship. The tree (through its roots) provide polysaccharides (energy) to the fungus.
While it is possible to eventually produce truffles by planting inoculated trees and liming without intensive management, the time to truffle production is at least 12 years. You don’t even have to plant high-density. But if you’re paying $20 per tree (Garland’s price for a one-year old inoculated filbert or oak) and your goal is to produce a harvestable product as quickly as possible, Garland’s intensive method is the way to go.
Having experimented with truffle production for more than 30 years, Garland has his process down to a science. He is the founder of the North American Truffle Growers Association (NATGA), and is thought to be the only American producer of inoculated filberts and oaks who has sold trees to currently active truffle producers.
In recent years, Garland has made renewed effort to focus on truffle production on his own farm. He has even partnered with other landowners in North Carolina to help them with their truffle orchards.
In addition to the black Périgord truffle, Garland has also cultivated black Burgundy truffles, which are suitable for colder climates, such as those found in Pennsylvania northward. He’s also eager to try to cultivate Italian white truffles — something that has never been done anywhere before.
“This may be the place to grow them,” he said.
If anyone could solve that riddle, it would be truffle expert Franklin Garland.
by Karl H. Kazaks