How to Tell if a Tree is Alive: The Scratch Test Guide
How to Do a Scratch Test on a Tree or Shrub
A scratch test is one of the fastest ways to check whether a plant is still alive. The goal is simple: lightly remove a tiny bit of outer bark and look underneath. Green tissue usually means the plant is still alive. Brown, dry tissue usually means that section is dead.
Step-by-step
Start small. Check a small twig first, then move to bigger parts of the plant only if needed.
Avoid scratching the main trunk unless you need to. Choose a section near the end of the branch as this will be the newest growth.
Use your fingernail or a small knife to remove only a thin surface layer. You are not cutting deeply into the wood, but you do need to fully remove a piece of bark to see the core of the tree.
If the layer under the bark is green and moist, that section is alive. If it is brown, tan, or dry, that section is dead.
If the branch tip is brown, move farther down the stem and test again. Plants can have tip dieback and still recover from lower growth.
Only the outer portion of the tree and its leaves are actively living! By removing the outer layer of bark, you are exposing the "Cambium" or the actively growing portion of the tree. The cambium is where cells are dividing to create the tree's "Xylem" on the inside, and the tree's "Phloem" on the outside. The Xylem only transports water and mineals up the tree. It consists of the wood closest to the cambium. Dead Xylem tissue becomes the heartwood of the tree. The Phloem transports water, sugars, and other complex molecules up and down the tree. The Phloem makes up the bark closest to the cambium. Dead Phloem tissue creates the outermost bark.
Common mistakes to avoid
- Do not scratch too deep! You can introduce disease to the tree.
- Do not test only one dead tip and assume the whole plant is dead.
- Do not keep scraping the same branch over and over.
- Do not confuse green bark color on the outside with living tissue underneath.
What if the top is brown but lower branches are green?
This means the top of the tree has experienced dieback due to stress, but the lower portion of the tree may still be alive. In this case, please use our tree support form so we can assess if removing the dead portion of the tree is the best course of action.
Can I do a scratch test on shrubs too?
Yes. The same idea applies to all woody plants. Use a small stem first and keep the scratch minimal.
What if I am not sure what I am seeing?
Take a clear close-up photo of the scratched area and send it to us. We have decades of experience with this test!
Need help checking your plant?
Use our tree support form. You will be asked to provide photos of the plant, the scratched area, and the base of the trunk or stems. The clearer the photos, the better we can help!