Spalt Your Own Lumber: Optimizing fungal growth
I’m going to warn you all now, thars science in this here post! Buckle your seat belts for a little learning before getting to the good stuff (well, I think learning IS the good stuff, but I know others might disagree).
Before I begin a discussion of how fungi grow in wood, I’ll need to cover a little wood anatomy. When people start talking about wood and fungi, the idea of wood anatomical direction always comes up. So lets all get on the same page:
There are two directions of interest here – the long direction, which is up and down the tree stem, and the radial direction, which is ‘in and out’ from the pith to the bark.
Fungi tend to colonized up and down and in. Primarily, most growth is up and down, since the vessel cells in hardwoods are long connected tubes:
Take a look at the picture above. Fungi, like humans, will take the path of least resistance. And there is a heck of a lot less resistance in a nice, wide-open vessel (the big circles) than any of the smaller cells.
So what is going on here?
In your spalting tubs, you could just toss in some mushrooms and hope for the best. But why waste time waiting for the fungi to degrade enough cell wall to get to those nice, long vessels? You can save yourself a week or two by breaking open your mushrooms and rubbing the inside on the endgrain of you boards. It makes life a little easier for the fungus. It also makes for nice growth patterns, like this:
In the photo above you can see the progression of the fungus through the wood. Utilizing the areas of your spalted wood where the growth is progressing can make for very striking effects.
Fungi also grow in
Mmmmm, sugar! Blue stain fungi love it! The cells in wood that go in and out from the pith are call ray cells, and are packed with all sorts of tasty things that fungi love to eat. So ‘weaker’ fungi, like the blue stains, will tend to colonize in and out, getting as much as they can from the rays before someone else gets there first! If you’ve ever seen a wood cookie with blue stain fanning in and out from the center, this is exactly what has happened.
So, go forth and spalt quicker! Utilize end grain to get your fungi colonizing faster and remember, sometimes the progression of the fungi can be just as interesting as an entirely colonized piece!
The anatomical directions on wood
Photomicrograph of a hardwood showing the long vessel cells.
Fungi grow through the end grain on wood.