Eastern red cedar heartwood vs. sapwood

[forrestM]

not sure if this is the best place to post this question, but what causes Eastern red cedar heartwood to turn red? and will all the sapwood eventually turn to red heartwood as it ages? is there any other factor determining the ration of heartwood to sapwood other than age of the tree?

thanks
forrest

[doc henderson]

ERC is a very interesting and fun wood.  It saws nice, and is beautiful, well liked for rustic and otherwise.  As the tree gets bigger, it tends to develop heart rot, then ants tend to make a home there.  the sap wood is where the sap still flows and is also less rot resistant.  the heart wood is the older inner wood and channels are generally plugged.  Many trees have a darker heart wood than the sapwood, and the contents of the plugged channels is what I think is responsible for this color.  each year the innermost sapwood will transition to heart wood and a new layer of sapwood will emerge.  this is how the tree grows in the cambium layer just inside the bark, and also how the bark grows.  this is how a tree grows around stuff like cables, concrete, pipe wrenches ect.  trees grow in layers.  so the first branches may not get any higher.  the top gets taller but it adds wood, and you are not growing the original inner wood.  the first years of a tree (15 ish maybe) is juvenile wood and in hardwood can be unstable, and we avoid it or center it.  This is where the heart rot usually starts.  you can develop an allergy.  ERC is really a Juniper.  Juniperus virginiana.  There is a city in Luisiana named after this tree by the French.  the chemicals in the heartwood that give it the red/purple color, will oxidize in the air and sunlight and will turn more brown overtime.  It will stay the color we all love longer with a UV protected finish, and if kept out of the sun.  also the color change is very superficial and if planed or sanded, the bright color is just under the surface.  the direct answer to the sapwood color change is yes if it is alive, and no if you cut it down (i.e. and just let it age).  I am not sure about the age and sapwood ratio, but young trees are almost all sapwood.  there is usually some sapwood color dispersed in the heartwood.  the older trees may have less (as a ratio) as they age because you keep converting sapwood to heart wood.  they may have more as a cross sectional area, as it is located in the ever increasing outer circumference.  since the sapwood represents the new growth, I assume that conditions of the soil and moisture may play a role.  they grow like weeds here, and the ranchers want them gone as they shade large areas, and suck up lots of water, decreasing grass for cows.

https://en.wikipedia.org/wiki/Juniperus_virginiana

[doc henderson]

 

 

 

 

[DonW]

ERC is a very interesting and fun wood.  It saws nice, and is beautiful, well liked for rustic and otherwise.  As the tree gets bigger, it tends to develop heart rot, then ants tend to make a home there.  the sap wood is where the sap still flows and is also less rot resistant.  the heart wood is the older inner wood and channels are generally plugged.  Many trees have a darker heart wood than the sapwood, and the contents of the plugged channels is what I think is responsible for this color.  each year the innermost sapwood will transition to heart wood and a new layer of sapwood will emerge.  this is how the tree grows in the cambium layer just inside the bark, and also how the bark grows.  this is how a tree grows around stuff like cables, concrete, pipe wrenches ect.  trees grow in layers.  so the first branches may not get any higher.  the top gets taller but it adds wood, and you are not growing the original inner wood.  the first years of a tree (15 ish maybe) is juvenile wood and in hardwood can be unstable, and we avoid it or center it.  This is where the heart rot usually starts.  you can develop an allergy.  ERC is really a Juniper.  Juniperus virginiana.  There is a city in Luisiana named after this tree by the French.  the chemicals in the heartwood that give it the red/purple color, will oxidize in the air and sunlight and will turn more brown overtime.  It will stay the color we all love longer with a UV protected finish, and if kept out of the sun.  also the color change is very superficial and if planed or sanded, the bright color is just under the surface.  the direct answer to the sapwood color change is yes if it is alive, and no if you cut it down (i.e. and just let it age).  I am not sure about the age and sapwood ratio, but young trees are almost all sapwood.  there is usually some sapwood color dispersed in the heartwood.  the older trees may have less (as a ratio) as they age because you keep converting sapwood to heart wood.  they may have more as a cross sectional area, as it is located in the ever increasing outer circumference.  since the sapwood represents the new growth, I assume that conditions of the soil and moisture may play a role.  they grow like weeds here, and the ranchers want them gone as they shade large areas, and suck up lots of water, decreasing grass for cows.

https://en.wikipedia.org/wiki/Juniperus

And the smell, mostly in the hart wood. I think it's what makes this wood interesting more than anything.

[doc henderson]

 

 

here is a table leg, with an example of the sapwood inclusions.  the roots form what I (and a few others call) lobulations, and bark inclusions.  so the bottom of the base log may have heart rot, and lobulations with bark inclusions.  that is why there is a different scale for ERC to account for loss of board feet based on the nature of this wood/tree.

[doc henderson]

 

 

[firefighter ontheside]

I would expect that cedars growing out in the open and have limbs all the way down to the ground are going to have more sapwood than those growing in forest conditions.  The trees growing in more crowded conditions are competing for sunlight and grow slower on average.  Their lower limbs tend to self prune and die off.  I like these trees with fewer limbs in the 9 or 10" range for lumber.  They don't have heart rot and bark inclusions like the big ones tend to have.

[Don P]

Pretty cool,

Hexane and methanol extracts of heartwood, bark/sapwood and leaves of twelve taxa of
Juniperus from the United States were assayed for antifungal and antibacterial activities.
The hexane extract of the heartwood of several junipers appeared comparable in
antibacterial activity to streptomycin. Antibacterial activity of the hexane extracts from the
bark/sapwood of J. monosperma and J. californica were comparable to streptomycin. No
appreciable antibacterial activities were found in the leaf extracts from any species ...

[doc henderson]

could have put this in my view from the office this am.



 

still working the sand, thin coat, sand on the tables.

 

 

[Don P]

I happened across this the other day

Hexane and methanol extracts of heartwood, bark/sapwood and leaves of twelve taxa of
Juniperus from the United States were assayed for antifungal and antibacterial activities.
The hexane extract of the heartwood of several junipers appeared comparable in
antibacterial activity to streptomycin. Antibacterial activity of the hexane extracts from the
bark/sapwood of J. monosperma and J. californica were comparable to streptomycin. No
appreciable antibacterial activities were found in the leaf extracts from any species ...