Pacific Northwest Truffles

[Alana McGee]

The following was posted by a student in another forum. I have moved it here and will respond in another postI’m trying to get an idea of the conditions that truffles like to grow in and habitat indicators if any.

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.

Where are they found in relation to the drip line of the tree?

Does the amount/type of ground cover help or hinder truffle production/locating?

Do they tend to be found on flat ground vs moderate or steep hillsides?

Do they tend to be found in lower areas of the terrain or close to logs or lots
of downed wood?

Do you ever find ‘fairy rings’ of truffles?

Are ‘fly clouds’ ever found over truffle areas?

Do you see a preference over fully shaded, partially shaded or sunnier areas?

Does the direction of the hillside have an effect?

Do you find mushrooms in general in the areas where truffles grow and if so are
there indicator mushrooms for 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.

[Alana McGee]

Thank you so much Alana. I know this is a complex question. Your reply was extremely helpful.
If we understand the type of area we should be in, it makes the chances of success a little better.

For our first morel hunt, we were clueless and we hiked for hours and found nothing. We were within 1/4 -1/2 mile of where people were picking like crazy. Habitat is everything!

As for the flies, we will see them with mushrooms quite often. I have not heard of truffle flies.

When we find mushrooms where they shouldn’t be, we just kid they didn’t read MD (Mushrooms Demystified by David Arora). 🙂

[Alana McGee]

Glad you have the MD 🙂 He’s updating it soon with more truffle related material. David actually, if you have access to him, may have places to suggest you look.

It is a BIG topic- and i’ll keep trying to answer your questions more specifically- it is always just, oh goodness, where do I start!

You are correct, Habitat is 1/2 the battle (if not more).

I’ll make another post with more specifics Re: Cal.

[Alana McGee]

The basics on Oregon Black truffles (Leucangium carthusianum- previous described as picoa)

BlackTruffleLaminate.jpg

This species btw does is exist in Europe, particularly France, and possibly N. Africa (we are helping with some studies on this at present) but it associated with different tree species than here in the PNW. In the PNW (California gets lumped into this too) It is most common with Douglas Fir. Possible with other firs/ Pine (lodgepole possibly in Ca) but primarily Douglas Fir.

They particularly like being under/ in sword ferns. It is not uncommon, to find them knotted up near rootballs of ferns. They can (like all black truffles- this goes for you on East coast too- we will get to that species soon, on that forum) they can be REALLY HARD TO SEE in the Duff/ dirt/ hummus. REALLY HARD. This is why precision alerts are great! so are headlamps.

[Alana McGee]

Hi Alana,

We’ve been waiting about 2-3 years now for the new MD. It’s such a huge project and with all the DNA work
being done, many names will be out of date when it’s published. lol! Nice to hear it will have more truffles in it!

I’ve met David a few times and I know a few people who know him very well. I’ll see if I can
get some ideas. But I have time.

Truffles are so different and we have so much to learn. We know it will take quite a bit of to learn about them and even more time in the forest. But time in the forest is always nice!

Something new to enjoy!

[Alana McGee]

And now for Whites, If I can get it to upload!

Whitetrufflelaminate.jpg

[Alana McGee]

Habitat

Habitat.jpg

[Alana McGee]

In reading more about truffles, for our area it seems there is a fairly large time frame
in which they can be found, i.e: late-winter to spring.

For many mushrooms location, elevation, rain and temperatures are big factors in when you will find then. Is this similar for truffles? If so, can you explain their effects?

Does the ground need to reach a certain temperature?

Do the days need to reach certain temperatures?

The other thing we notice with mushrooms is that for some species an area or patch of mycelium will produce 1 ‘crop’ of mushrooms for a week or 2 and other types might produce multiple ‘crops’ over a longer time period, upto maybe 4+ weeks – with the right weather conditions. Are there typical production or collection time frames with different truffle species?

I’m curious, because if you miss that prime 1 or 2 week period, you can miss the entire season.

[Alana McGee]

Actually by you- it’s more like late Fall through spring- provided you have moisture. That’s the caveat in California, you have to have rain/ or at least coastal moisture!

Elevation does play a role in fruiting. It is not well understood as there is not enough scientifically collected data- but from observational experience, yes. Stuff at Higher Elevation starts fruiting earlier.

As for temperature causing fruiting/ripeness: Wow- a big topic- it will depend on species. Studies have not been done (scientifically, to our knowledge) for native species in this regard. They have been done however on this for Perigord truffles (Tuber melanosporum), basically in the last year- so it’s a pretty new understanding. The oversimplified answer is for T. melanosporum fruit bodies to mature (aka become ripe) they need a temp spike downwards. Not freezing. It is more complex than that, and I won’t pretend to understand or know all about it, but that is the simple answer.

*Those of you who have orchards who are reading this (you know who you are!)- ask your consultant for specifics if curious because I am paraphrasing and condensing a lot. It may be different for T. aestivum/uncinatum and likely is for T. borchii as we know both those species have a much broader natural range. There is data out there for daylight hours fruiting temps etc for those species. There is not for natives.

In general truffles need moisture to fruit/ ripen. Our understanding of how they go about this is changing yearly. Again, this is varies from species to species. There is a lot we don’t know. We used to think they would take 6 months to grow (primordia to sporocrap to fruit body to ripening), now it is more likely they are more closely related to what mushrooms do with ‘fruitings’ and flushes.

It gets pretty technical if I start getting more in detail.

That being said, truffles will not all be ripe at the same time. They will ripen continually throughout the season. Oregon winter whites (oregon white truffle species in general) have a shorter season than blacks. In an Oregon white patch (for example) bunches of them can be growing, but only a few ripen at a time and then a week later more are ripe, then a week later nothing and then 2 weeks later, lots. We don?t know what environmental factors contribute for sure to the ripening.

Tidbit of data: North of Eureka on the coast in March of last year Oregon white truffles were fruiting. We found a couple in the Santa Cruz Mts in January- but it was SO dry.

Observationally we have noticed a different pattern with Oregon Blacks (Leucangium carthusianum) * also found in Europe and classified as Picoa* and we feel like ripening and fruiting & growth is related to rain events several weeks prior- but this is observational. To my knowledge there is not published data anywhere on it.
I’m curious, because if you miss that prime 1 or 2 week period, you can miss the entire season.
This isn’t a problem with truffles. Yes you can miss big ripening events, yes, but if you have a productive spot, it will produce continually in varying amounts over the course of the season aka months.

For Wa & Or (BC tends to fruit a little sooner we think, CA later? but again, limited data) Oregon winter whites (T. oregonense complex*) are generally best in Dec/ Jan/ Feb (but we will find them Nov thru March- again depends on local weather patterns)

*some of the complex can be found slightly earlier

Oregon Spring whites (T. gibbosum) they call the ?june? truffle. We found them in January last year (they fruit when they fruit!), but very few people have large patches of Oregon Spring whites. I know two people in oregon who may have the only claim/ knowledge on commercially productive T. gibbosum sites and they tend to fruit in late april/ may/june. My knowledge on those is more limited. We find a few here and there mixed in in one of our productive black sites, but we don?t find a ton. Most would likely confuse them for Winter whites as well but there are subtle differences. Again, it is actually considered a complex species (as in there are genetically many, not complex as in confusing)

Blacks tend to have a longer season. We have student who found them in July. We are finding one or two now, but not many. Again, Nov- April really, but best late Dec to April/May even! One year was I finding a decent amount by beginning of Nov, but again it totally depends on rainfall, and temperatures.

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