Reply To: Pacific Northwest Truffles

Alana McGee

In answer to your questions Annie- much of this is easier to explain in person, and it is a complex topic, it’s not simply go here, find truffles. We suggest if you are really interested in learning more about habitats etc that you attend either any of the truffle festivals, talk to experienced truffle harvesters, or a seminar hosted by us or another mycological expert on the subject, or all of the above. It is much too vast to type out here, but I will try to be concise.
I’m trying to get an idea of the conditions that truffles like to grow in and habitat indicators if any.

Each species of truffle prefers different things, so it is hard to generalize. We have PDFs we will post in this forum once we have responded to your questions which cover some brief archetypes of what to look for for the most common culinary commercial species in the PNW/ California.
Are there indicators in your forest areas that clue you in to the possibility of truffles – other than specific tree species since truffles are mycorrhizal.

Animal activity- we will post pictures of this to follow so this post does not become cluttered. there can be indicator species (this will vary from truffle species to truffle species) there are also other habitat markers. Tree age, soil type, etc. BUT keep in mind, while science has started to narrow down perimeters for truffles, much is unknown or not well understood. What makes for productive (as in very commercial) habitat does not necessarily mean the absence of which means no truffles. For example- you typically don’t find Tuber oregonense (oregon winter white) on steep rocky hillsides- yet we do and have, regularly. You typically do not find Tuber oregonense complex (there are actually many species which are very close) on anything but Douglas fir- but we have a spot that produces them on Scotch pine and noble fir. Etc.
Where are they found in relation to the drip line of the tree?

In a true forest that isn’t a orchard, this really doesn’t come into play. You have a canopy, there isn’t a distinct drip line. They can be found VERY far form the drip line. i.e. I reference finds found in Home Depot parking lots…. VERY far from the douglas fir from which the mycorrhizae is attached. They can be in the middle of a grassy field.

In orchards it is a different story- but even then you can find them equidistant between two trees- but there is a specific reason for that due to the nature of that specific Tuber species I am referencing (Tuber melanosporum- Perigord truffles). It varies, depending on species! Tan Oak may have more a a ‘drip line’ like you are referring to. You will rarely find them right at the base of the tree- but up to about 30% beyond the drip line (I am referencing white Tuber species complex here)
Does the amount/type of ground cover help or hinder truffle production/locating?

A lot of undergrowth certainly makes it difficult to harvest, and it frankly isn’t worth it- Much of this is better explained in photos (which we do have but a lot of this is info covered in seminars if you attend them). Truffle species tend to inhibit (to some degree) the growth of other flora- so very thick undergrowth isn’t generally worth your time. Again, it is truffle species specific. Our native species do not necessarily create the same kinds of br?l?e effects you see on European cousins- but again, that is partially due to hosts trees.

Ideally you want as little undergrowth as possible. Again, we will post photos when we get a chance.
Do they tend to be found on flat ground vs moderate or steep hillsides?
Again, this is species specific. Very steep, again, harvesting truffles on steep terrain is difficult. We don’t recommend it. LC (Leucangium carthusianum) does like riparian drainage. They like it wetter.
Do they tend to be found in lower areas of the terrain or close to logs or lots
of downed wood?
Depends on where you are located. In areas of little water/ drought- like where you are, yes the mycelium will like to congregate near moisture, so the edges of logs where water collects and seeps.
Do you ever find ‘fairy rings’ of truffles?

No. You do, with Oregon white species, however occasionally have what we call ‘nesting’. They will be near or on top of one another. This is much rarer with blacks.
Are ‘fly clouds’ ever found over truffle areas?

Have you been reading about Italians harvesting via watching truffle flies? No. In the US, no. We do have bugs that eat and damage truffles, such as Collembola, but no.
Do you see a preference over fully shaded, partially shaded or sunnier areas?
TOTALLY depends on where you are, aspect, time of year etc.
Does the direction of the hillside have an effect?
It absolutely can. Again, depends where you are, precipitation, heat, etc. Here in Wa/ BC we focus on Southern facing hillsides because they are warmer. That shifts about Roseburg, and you would start to want to face north (when we are talking about Doug fir plantations), but in CA, wherever you have water! This is different though for different microclimates. Example, not necessarily the same for Oak.

On the coastal range in the Santa Cruz, you want where moisture clings- West facing, etc. See- it is a massive topic and very dependent on a lot of different variables!
Do you find mushrooms in general in the areas where truffles grow and if so are
there indicator mushrooms for truffles?

Depends on species of truffles you are looking for. Cantharellus tends to like some of the same habitat as Leucangium carthusianum, but just because you have cantharellus, does not mean you have black truffles.

This is just a brief overview mind you. Feel free to ask questions, but we also will try to post photos. Do understand though, it is a big topic.