How to Identify & Select Trees for Mushroom Logs (With Pics)

Selecting good wood for plugging can make a big difference in colonization success, harvest quantity, and project longevity.

We want our efforts to be worth more, right?

We’ve gone through the uncertainty of selecting a mix of flawless, mildly blemished, and defective logs, and we’ve seen what works and what doesn’t.

Before we started, log and wood selection was the most difficult topic to find good information for. So I’ve made it my mission to spell out and show clear directions in this post for you. (Prepare to discover the real difference between hardwood and softwood as well!)

See: 9 Best Mushrooms to Grow on Logs (From Easy to Hard)

What are mushroom logs made of?

Kind of a seemingly silly question, but there are many types of wood that aren’t going to make good mushroom logs. Multiple quality characteristics need filtering to make mushroom logs out of the best-choice wood.

Mushroom logs are made of healthy, undamaged hardwood from various tree types. Each gourmet mushroom has a preference for tree species. While most hardwoods are adequate, shiitakes, for example, grow best on oaks. Good wood choices yield a higher return because the mushrooms will produce better. 

For mushroom cultivation, we use hardwoods and soft hardwoods such as:

SpeciesCharacterJanka hardness rating
Ironwood(Hardwood)3,260 lbf (14,500 N)
Maple(Hardwood)1,450 lbf (6,400 N)
Oak(Hardwood)1,360 lbf (6,000 N) – 2,680 lbf (11,900 N)
Beech(Hardwood)1,300 lbf (5,800 N) – 1,686 lbf (7,500 N)
Other birches(Hardwood)1,260 lbf (5,600 N) – 1,470 lbf (6,500 N)
Paper birch(Soft hardwood)910 lbf (4,000 N)
Alder(Soft hardwood)590 lbf (2,600 N)
Poplar(Soft hardwood)540 lbf (2,400 N)
Basswood(Soft hardwood)410 lbf (1,800 N)
The listed species are all considered hardwoods. Some hardwoods are softer than many softwoods and we call those soft hardwoods.

The most common hardwoods for mushroom cultivation are maple, oak, beech, and birch. The most common soft hardwoods for mushroom logs are paper birch, alder, and poplar. Softwoods are not commonly used for mushroom cultivation.

Ironwoods are pretty valuable for long-lasting firewood and we reserve most of ours for this purpose. Ironwood is also hard on drill bits and they dull much faster than necessary.

On the other side of the spectrum, basswoods burn as brisk as a ‘mother-walk’. Less valuable for fire, but also feed mushrooms less than poplars and above. We’re most likely to reserve basswood for kindling, but many mushroom growers like to use basswood.

Poplar, beech, oak, and maple are our personal top choices. They offer plenty of substance for mushrooms, their barks don’t scar and peel easily, and are abundantly available on-site.

As confusing as “hardwoods” and “softwoods” are, their classification is very helpful for mycology purposes. The terms are confusing because some softwoods are actually harder than some hardwoods and vice versa. Their classification has little to do with strength or density and more to do with physical structure. Hardwoods are angiosperms and softwoods are gymnosperms.

Softwood trees produce more sap than hardwoods. And since sap is antifungal, we want to inoculate logs with less of this juice!

Most mushrooms that grow around softwoods are usually symbiotic. For example, boletes thrive around pines because of their symbiotic relationship.

One of numerous edible chicken fat bolete mushrooms we foraged on property under the pines and dehydrated for later consumption.

Non-symbiotic mushrooms favor growing around hardwoods because they drop a consistent food supply of wood. Hardwoods tend to be deciduous which drop leaves, grow fast, and die often. Coniferous trees grow slowly and live very long. As hardwood trees die or drop limbs, mushrooms colonize them quickly by all sorts of hungry mushrooms—their sap runs much quicker than softwoods (conifers).

Now that you know about hardwoods for mushroom cultivation, I’ll show you

  1. how you can identify trees, and
  2. introduce a few more vital ways to pick the best logs for mushroom plugs.

Related: Where to Find Fresh Wood for Mushroom Logs (9 Places)

1. Choose and identify tree species

Any hardwood may do fine for most log-grown gourmet mushrooms. But why not go the extra step to find out the preference?

By supplying the preferred type of wood for any given mushroom species we are more likely to get a favorable harvest.

To find the preferred wood for your mushrooms:

  • I wrote about the 10 Best Mushrooms and included the ideal wood choice for each mushroom log method.
  • You can also forage for your favorite mushrooms and take note of what tree they are naturally growing on in your area.

Step 1: Choose your mushroom strain (oyster, lion’s mane, shiitake, etc)

Step 2: List out the preferred wood species of the choice mushroom

Tip: we grow multiple mushroom species. Their wood-type preferences vary but also overlap. I list out the ideal wood types for each, then choose to go after the most ‘popular’ option.

For example; we are doing lion’s mane, shiitake, oyster, and chestnut mushrooms.

  • Lion’s mane loves: beech and maple
  • Shiitake loves: alder, beech, maple, and oak
  • Oyster loves: aspens, willows, and cottonwoods, but is also very easy-going mushroom and we find them when foraging on oaks, maples, and poplars.
  • Chestnut loves: aspens, beech, birch, maple, and oaks

We chose to go after beech and maple since we find them easy to identify during dormancy and all our mushroom options will thrive.

I refer to North Spore’s tested mushroom strain preference chart for all sorts of mushroom strains and tree species, and you can use the coupon code QUALITYSPAWN to discount all their equipment including plug spawn.

Step 3: Identify the tree species you’re after for harvest

Below, I will talk about some identifiers for maple, oak, poplar, beech, and birch trees so you can select trees to cut. If you don’t need help here, skip to the section on how to pick undamaged quality logs so you know what to look for when buying or sourcing any log!

The easiest way to identify these trees is by their leaves. Especially when differentiating between oak and maple! Their barks look similar and the appearance of nearly all bark changes with age.

Maple, poplar, beech, birch, and oak leaves resting on Sadie, happily as she is.

An easier way to identify the tree by bark is by comparing each. Because differences add up!

How to identify maple trees in winter for mushroom logs

Feast your eyes on these images, for if the leaves aren’t on the trees . . . and you’re looking for logs . . . and you didn’t tag your trees before fall—you just might be able to tell the difference.

Maple bark, regardless of age, always appears like it has a lot of depth. The plates are long and uninterrupted. The crevasses can appear deep and wide, or narrow and dark.

Young maple
Mature maple tree
Very mature maple tree with gnarly bark

You’re likely knot going to be using wood from a very mature maple tree (far right) because those would simply be unmoveable mushroom logs!

Younger wood (far left) is about a 4″ diameter. Cut that down to 3-4ft lengths and they will be humanly manageable. The plates on young maples are raised like mature maple bark—the cracks are true crevasses, and young bark appears quite pale compared to old.

How to identify oak trees in winter for mushroom logs

Oak logs look rougher, shallower, and almost flakey in comparison to maple bark, but aren’t literally flakey. Their plates seem less prominent and frequently interrupted, I think that is where the word “flakey” strikes the mind.

Mature oak too large for mushroom logs
Young oak 6″ diameter

This article was originally published on foodforestliving.com. If it is now published on any other site, it was done without permission from the copyright owner.

Young oak bark is less rough-looking than mature oak bark. The bark is quite surface level, unlike maples. The plates seem sunken, and the “cracks” are like raised swollen fissures. Young oaks don’t appear pale as youthful maples do.

How to identify poplar trees in winter for mushroom logs

Mature poplar bark is like a shallower but uniform version of maple. The plates are neat, flat, and bold with less depth than maple.

Young poplar near ground level
Young bark from the top of a mature poplar
Mature poplar bark near ground level

Young poplar bark, particularly white poplars resemble birch without the paper. The young bark of new limbs is smooth like beech trees. You’re most likely to use the far left picture of a young tree rather than an unreachable limb from the canopy.

How to identify beech trees in winter for mushroom logs

beech bark feels and looks like a smooth, matted finish on a white-sand beach (the white sand I’ve seen is grey). Other than young poplar bark, it’s the smoothest bark I’ve ever seen in the north. Unlike poplars they don’t become rough with maturity; they stay the same. Beechwood is very different from all the other hardwoods around; its identification is as obvious as paper birch.

Beech tree with its tough leaves
Beech tree bark up close

Another obvious giveaway is their leaves! They usually hang on to at least some of their leaves well into late winter.

How to identify birch trees in winter for mushroom logs

Like all the trees above, there are many varieties of birch, and between them, their bark can look quite different. We have lots of white birches here, which are soft hardwoods. The papery bark that peels to pink is quite obvious to distinguish as white birch.

The bright white bark has black horizontal lines from top to bottom and the oddball of Chaga!

Identifying trees in winter for mushroom logs

In all honesty, identifying trees with certainty without leaves is difficult! Each tree type also has a wide variety of species that differ in appearance. You need to examine the leaves, bark, and flower to be totally convinced. Based on bark alone you’re most likely to be confident about birch, beech, then poplar. Maple and oak are difficult to really distinguish between by bark alone unless you’re already quite familiar with your forest.

The good news is, most mushroom varieties will do generally well with any hardwood with oak and maple being the most popular choice. So if you’re gambling between oak and maple, getting it wrong isn’t the end of the world.

Avoid cutting endangered tree species in your area. Look up your local endangered tree species and avoid cutting healthy ones down.

2. Identify healthy trees for quality logs

After you find the right tree type, you’ll want to ensure it’s healthy before going through the effort of cutting it down and cleaning it up.

Healthy trees can be tough to spot in winter while all are dormant and without leaves.

It’s easiest to know you have a healthy tree by becoming familiar with the trees of your harvesting area in spring and summer. So keep this in mind for next time!

For now, you can do a few simple checks to differentiate between a dead or healthy tree during winter.

  1. Look at the bark from top to bottom to see if all bark is intact and healthy looking. Are there cracks, missing sheathes, or separation from the trunk?
  2. Check if the tree has leftover leaves hanging on it. Leaves on trees during winter aren’t required to determine a healthy tree, most healthy trees won’t have leftover leaves in winter. Some species, however, such as beech, hold onto their leaves throughout most of the winter and are very easy to spot as healthy trees, as leaves are a sign of growth.
  3. Check the canopy. Are there broken limbs hanging or broken? Are buds visible (even way up there)?
  4. Look for woodpecker damage. Woodpeckers tackle trees that are on their way out, as tasty bugs are present under the bark of dying trees.
  5. Look for suckers. Suckers often shoot from trees that don’t plan to live a long healthy life. Suckers are the main trees’ replacements.

3. Check individual logs for damage & disease

Essential inspection checks for good mushroom logs

Although you checked for a healthy tree, you need to investigate each log too.

Whole trees may appear totally healthy but may still present damaged or dead areas. Some logs may also have damage from the felling of the tree.

Your logs are less likely to have damage from the event if you cut your trees down while dormant, as the bark is less fragile during dormancy.

How do you pick mushroom logs?

Well-chosen logs can go a long way toward a good mushroom harvest.

Ideal mushroom logs need moisture, abundant sapwood, and bark integrity. Soak wood that has become too dry for 1-2 days before plugging. The sapwood layer provides vital nutrients and moisture retention. Undamaged bark reduces competition and retains moisture during colonization.

Every mushroom log should go through several but simple inspection checks before you commit to inserting your plug spawn.

  1. The weight
  2. Bark ‘seal’ or lifted bark
  3. Cracked bark
  4. Dark spots
  5. Sapwood to heartwood ratio
  6. Drill site bark tact
  7. Drill hole color
  8. Drill scrap color

A heavy log is a healthy log. Light wood is a sign of wood that has been long dead.

Each wood species will have various weights, so compare logs between the same species. If any hardwood log is abnormally light, it might not be the best choice for using your plug spawn.

Do mushroom logs need bark?

Bark that lifts off the wood at any point is not a good sign. Healthy trees shed their bark but replace it with new, snug bark. If the bark is lifting off, it’s a sign of illness as it was not adequately replaced, and your mushroom log will dry out too easily.

Bark serves many required functions for productive mushroom logs and without it, you’d be using a ton of wax.

Mushroom logs need undamaged bark to thrive for a couple of reasons. While the mycelium is colonizing the wood, the bark will keep it from drying out too fast. During this sensitive time, bark hinders other fungi from competing with your strain. 

Before and after cutting down any hardwood tree for mushroom logs, always inspect the quality of the bark.

If you only have what you have and there is some damage to the otherwise healthy bark, wax the exposed areas. The most important thing is to use sections of a tree that was healthy and alive before cutting it.

Tree bark is resistant to breakage during dormancy, so cut wood in winter to retain quality when felling.

Over time, the logs will lose bark as the mushrooms fruit and decay the log. By that time, they had already claimed the territory, and no competition could invade or defeat them. But it’s best to keep your bark intact for as long as possible!

When the bark is gone, keeping logs moist is more important than before. Don’t allow your mycelium to die off from underwatering.

Which is better heartwood or sapwood?

Maybe you have or haven’t heard these terms, but you should be wondering about the difference and which is better for your mushrooms.

It’s best to choose logs with little heartwood and a lot of sapwood. Sapwood carries all the nutrients of the tree and your mushrooms will live off it.

In the photo above you can see the dark center is “heartwood” and the wood around it is sapwood. The more sapwood, the better the log for mushroom cultivation.

Mushroom log selection summary

Whether you are buying wood or cutting it yourself, all of the following standards will apply. This list summarizes everything you need to consider when picking mushroom logs.

  1. Find the preferred type of wood for the chosen mushroom strain
  2. Use wood from a healthy young tree to reduce competition (e.g. don’t use a birch that was infected with Chaga!)
  3. Check individual logs for damage and disease

Extras:

  1. Use trees with a 4″-6″ diameter
  2. Cut logs to a manageable size (3-4 ft long)
  3. Plug logs that are 2-4 weeks of “age” from when they were cut
  4. Avoid using dry logs with cracks bigger than the thickness of a dime
  5. If you have a quality log that is overly dry soak it for 24-48 hours prior to plugging
  6. Find logs with thick sapwood layers for plenty of consumable nutrients
  7. Search for dormant-cut logs for the best quality

Next step:

Rachelle

While Rachelle's hands are clean for the keyboard, she enjoys writing and designing creative content and resources. You will most likely find her outside planting a cabbage, foraging berries for breakfast, and collecting herbs for year-round tea or making food.

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