Why Is Heartwood Darker In Color Than Sapwood? (All You Need To Know)

Woodworking projects give rise to many questions. One of the most commonly asked questions among them is this. Why is heartwood darker in color than sapwood? There are plenty more. But this is the only primary concern I wish to address in here.

Do you know what’s essential to good craftsmanship and woodworking skills? It’s basic knowledge regarding the internal and external structure of different types of wood. Only when you feed this kind of information to your brain can you make well-informed decisions about choosing the best wood.

The majority of woodworkers tend to get confused when it comes to selecting between heartwood and sapwood. And the topic associated with “Why is heartwood darker in color than sapwood?” is even more confusing.

So what you need to do here is read the entire article to get rid of all the confusion. At the end of the post, you’ll be able to answer the question. And many more such questions related to heartwood vs sapwood strength, formation, appearance, etc.

Definition of Heartwood and Sapwood

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The heartwood of a tree is the main supporting core. It contains dead tissues, which don’t transport nutrients and water to the leaves and branches anymore. Even so, it acts as the central support system of the living tree.

Heartwood might be considered dead. But that doesn’t make it weak nor does it start to decay. So long as its outer layers of protection remain undamaged and intact.

Whereas sapwood is the layer located within the tree’s cambium layer. It consists of fresh, young wood. That means sapwood function involves transporting nutrients and water. To the branches, leaves, and other parts right from the roots!

The Most Amazing Thing About Trees

Formation of Heartwood and Sapwood

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Let’s discuss how sapwood comes into existence. So why is heartwood darker in color than sapwood? You’ll find out soon enough.

Tree structures consist of components known as cambium cells. They are located within the tree’s phloem layer. And it’s this particular layer that forms the cambium. Cambium is nothing but an incredibly thin water layer. Cambium cells have the ability to multiply during the tree’s growth. That means they are in charge of increasing the diameter of branches, roots, and trunk.

So it’s only logical to assume that cambium also leads to the development of new sapwood. When fresh sapwood is formed, the internal layers die and turn into heartwood.

Therefore, sapwood and heartwood are the outermost and innermost layers respectively. The latter is the core while the former is the softer layer present outside this core.

Appearance of Heartwood and Sapwood

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Here’s the answer to why is heartwood darker in color than sapwood?

The formation of heartwood kills the cells of sapwood found in that region. Is that correct? The death of sapwood is marked by the presence of extractives like resins and tannin.

These elements are also responsible for the dark color of heartwood. They make the wood more immune to decay and such microorganisms. As these cells weaken, the vessels located in that part get blocked. And stop transporting sap to the other areas.

The growth rings around heartwood are the best way to distinguish it from sapwood. The former’s rings are richer and darker. In comparison to the other tree layers! Whereas sapwood is lighter in terms of color! And softer in terms of texture!

So at this point, it’s quite clear why is heartwood darker in color than sapwood. The darkness in color is an outcome of the inevitable aging process.

But here’s another thing you should know about the differences in color between heartwood and sapwood. Tree trunks have darker sapwood as compared to heartwood. That’s because factors such as staining by microorganisms and injury are also a part of the picture.

Heartwood vs Sapwood Strength: What Is Better For Woodworking?

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Wood is incredibly valuable for construction tasks. Using the right kind of wood is what guarantees greater results of your finished project. So let’s find out the differences between the strength of heartwood and sapwood.

Now you already know that heartwood is the tree’s dried up part. The formation of this wood is a process that makes it decay-resistant and strong. In fact, it’s also responsible for bringing about the darker color.

It goes without saying that sapwood has extremely rich moisture content. This is great news for the tree, right? However, it’s anything but the same for your wood flooring and other such wood-related projects. The high level of moisture present in sapwood is what increases its chances of decay. Along with fungi infestation!

Another important point to note here is that sapwood is prone to shrinking excessively. Since it contains moisture, the wood tends to shrivel up when dried. And that doesn’t sound like something you would want to use for wood flooring or furniture, does it?

So the likelihood of heartwood giving you better results than sapwood is quite high. The same applies to an important factor like durability.

Even as far as aesthetic appearance is concerned, heartwood outperforms sapwood. Its rich dark brown shade looks more appealing in wooden furniture.

And lastly, sapwood stains easily. Environmental elements such as fungus don’t take time to compromise the structure and appearance of the construction. So it’s pretty obvious how and why heartwood is better than sapwood.

Have You Got It?

Why Is Heartwood Darker In Color Than Sapwood

So in the end, why is heartwood darker in color than sapwood? It’s because the former goes through the aging process. Heartwood is the dried up core of the tree. It doesn’t contain as much water as sapwood.

The presence of extractives chemically alters the structure and appearance of heartwood. These include resins, oils, and minerals. There are many contributing factors, as you can see.

The densely packed growth rings are what mark the difference between heartwood and sapwood. Especially during the winter and autumn months!

You should also know that heartwood has a unique pattern. You’ll spot little balloons known as tyloses. Such an interesting formation is something that is non-existent in sapwood. So there’s another clear indicator differentiating the two.

Final Words

So now do you know the answer to why is heartwood darker in color than sapwood?

This means your brain is well equipped to make the most suitable decision. Selecting wood for your DIY undertakings doesn’t seem so confusing anymore. I hope.

All the best for your woodworking projects. And I kindly request you to share the post with fellow woodworkers and DIY enthusiasts.

If there’s any more useful information you would like to share, please do so. I have not created the comments section for nothing. So don’t think twice before dropping in your thoughts and feedback.

Thank you for reading and visiting. See you again soon, hopefully.

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