What Happens When a Tree Dies?
The great tree beyond
While trees live a long time, they do eventually succumb to the woody grim reaper. For the delicate willow, that’s usually around 30 years. For the gnarled juniper, death may not come for 700 years in a healthy environment. And many causes, from careless construction work to dangerous fungi, can bring trees down well before age catches up to them But when the time does come, what happens to the tree — and what does that mean for home and property owners?
It’s not always easy to tell when a tree is truly dead, and not just dormant over the winter (when many dead trees fall) or still struggling with a problem like lack of water. To help out, we are breaking down all the steps that occur when a tree really dies, what to watch out for, and why dead trees can pose a risk near your home if you aren’t aware of them.
Stages of a Tree Dying
What, exactly, does the a tree go through when it dies? Let’s go over the signs you’ll notice and what happens to the tree when it starts to decay.
Leaves and Needles Die Off
It can be difficult to tell when a tree begins dying. There may be no obvious signs at first, as trees can weather problems very well for years at a time. But even the most stubborn trees start showing signs when death comes, often beginning with leaves and needles.
Leaves will wilt, yellow, and eventually fall. If it’s near the fall season, leaves often fall early and won’t return in the following spring. Evergreens like conifers will show yellowing or graying needles that they will eventually lose as well.
Note that when trees die, they don’t always die on every side equally. It’s fairly common for one side of a tree to experience these symptoms and die while the other side lives on for much longer. However, this also causes long-term problems that usually mean the tree won’t survive.
The Tree Stops Growing
The next major sign of tree death is no new growth. The tree will stop putting new shoots and will either produce small, weak leaves or no new leaves in its spring growth season. This signifies that the tree no longer absorbs enough nutrients to maintain growth. That can happen in drought conditions or if a tree’s leaves are destroyed, and it doesn’t have enough resources to grow them back. It also happens when a tree’s sapwood is destroyed or its roots are cut or destroyed by fungi, bugs, soil compaction, and other problems.
With care, a tree may still recover at this stage if problems are reversed — depending on the amount of damage that’s been done. The timeline can vary greatly: The most destructive fungal diseases can destroy a tree in months, while a slow drought can drag the process out for years.
Roots, Bark, and Branches Start to Die and Decay
If a tree doesn’t have a chance, its roots and more vulnerable branches will die off. At a molecular level, the cellulose of the tree has begun to disintegrate. Some trees die from the outside, while others decay from the inside, especially when infested by bugs or diseases.
When a tree weakens enough, its bark starts to crack or fall off altogether (also seen in old age). Trees need their bark to protect vulnerable wood, including their sapwood and heartwood, so this is a clear sign that things are probably too late for the tree. Beneath the bark, the once green and healthy wood will have turned gray and dead as sap ceases to flow.
Once a tree progresses in this stage, its branches die entirely. This creates a new risk for larger trees: Heavy branches are likely to break off and fall, even before the rest of the tree dies. They can hit rooftops, fragile patio furniture, and even windows. When branches die like this, it’s essential to remove them, or even the entire tree, for safety.
Rot Sets In
The above decay process opens the dying tree up to all sorts of attacks. Bugs and fungi start feasting, hastening the process. With sap no longer flowing, all the living wood of the tree dies and becomes even more susceptible to rot. Some experts classify tree rot by color—white rot is mostly cellulose decay, while brown rot signifies more lignin, the tougher, rigid structure of the tree.
You’ve probably seen trees, both fallen and standing, sport large mushrooms and fungal growths. This is the stage where all those mushrooms find purchase and start growing onto the tree. Likewise, more burrowing bugs hasten the job, and you’ll start to see termite infestations or similar developments. The rot occurs quickly, depending on the tree’s climate and condition. If a tree dies by sudden causes, such as a lightning strike or fire, then this decay stage may be all that’s left.
The Tree Falls
With its roots decaying and its structure falling apart, no tree can stand for long. Gravity eventually forces it to fall, usually after a brief leaning phase. Trees can take a long time to fall in a deep forest because they are protected from the wind. But when more exposed, windstorms will usually provide the final push.
Decomposition Takes Care of the Rest
With the tree fallen, it becomes a new part of the habitat. The decomposing matter becomes a home to all kinds of insects, worms, mosses, bacteria, and fungi, which continue to break down the tree’s most vulnerable parts.
The toughest parts of the tree, usually the bark shell, tend to last the longest and even provide shelter for wildlife like lizards and badgers. Since a fallen tree usually clears a space for more sunlight, it’s often prime ground for a new sapling to start growing, too. Eventually, the tree’s remaining bits are mixed into the surrounding soil, providing valuable nutrition.
This final decomposition process can take many years to complete, during which time the tree hosts its own new and valuable habitat. It’s so valuable that some experts believe our forests need more dead trees, not fewer.
What To Do When a Tree Is Dying
The line between a living and dying tree can be murky right up until a tree falls from decay. Trees die very slowly and can come back to life unexpectedly, as you’ll sometimes see when stumps start sprouting new shoots. But it all depends on what the tree is struggling with and its unique conditions.
In some cases, you may be able to save a tree or at least part of it. A tree that’s only suffering from lack of water is easier to save than a tree dying from a blight or other fungal infection. And while trees can survive if a significant portion of their roots die, if enough roots are crushed, cut, or choked, then there’s not much you can do to help.
With so many unknowns, we suggest professional advice. If a tree is significant or looks like it can be saved, contact an arborist near you for a consultation. They’ll be able to offer tailored advice on whether a tree can be saved or should be removed before it poses a risk to nearby trees.
When Should You Remove a Dead Tree?
Dead trees pose particular dangers in your backyard or elsewhere on your property. Dead trees fall very unpredictably and often unexpectedly, especially in windstorms. Once a tree reaches 20 feet or higher, it will cause significant damage if it falls on a fence, your roof, other plants in the yard, or a deck or patio. Even worse, dead trees can hit a neighbor’s or adjoining townhome, causing liability headaches. If they strike nearby power lines, it can create serious electrical hazards that only power companies and professionals are equipped to handle (plus the possibility of a fine due to negligence).
All that means you should take down a dead tree quickly if it’s beyond saving or has started posing a danger. This brings up a new set of problems. Cutting down a larger tree requires experience, preparation, and tools like larger chainsaws and tree wedges. If you’re not prepared, we suggest looking for a tree removal service near you.
Professionals can cut down trees quickly and safely with the right tools, although you must handle labor costs. Most tree removals start around $200 and can rise to $2,000 for large, complicated projects. If hiring a pro, schedule the visit quickly before colder months and storms arrive, increasing the chances of downing a dead tree.
Frequently Asked Questions
Yes and no. In a natural setting, dead trees play a significant role. As we discussed, they are broken down by fungi and other organisms until they provide important nutrients to the nearby soil and nurturing places where wildlife and plants can safely survive.
But that role is relegated to natural forests and groves. When trees die in yards or gardens, that normal decay process causes problems. First, the rotting wood attracts bugs and, when dried out, can create a fire hazard, so removing even stumps from your yard is always a good idea. Second, if a tree dies from disease, letting it linger makes it much easier for the disease to spread to other, similar species, which is how entire groves can be wiped out. Third, it’s a long and unsightly process that most people don’t want in their landscaping.
Usually, trees die from a combination of factors since they become more susceptible to disease as they weaken. However, a particular danger in residential areas is soil disturbance through construction or landscaping. Soil compaction from equipment, excavation, or landscaping can crush roots near the surface that trees need to survive or choke roots so they can’t get enough nutrients.
The problem with these soil-related deaths is that spotting the damage when it happens is challenging. Since trees can take years to die, it’s not always apparent what killed them. Always take care when doing any kind of landscaping around trees.
There’s no easy answer to this common question. Trees are in danger of falling when their roots die, and they lose their support system. With causes like root rot, that can happen very quickly across a matter of months. Other trees may lose their roots slowly. Once a tree has become fragile enough, it can take weeks or even years to fall, depending on the local weather, the angle the tree grew, and other factors.