Have you sprayed too much insecticide on your tree? Applied too much fertilizer? There may still be a chance to save your plant. Here is how to save a poisoned tree.
Many gardeners have learned the hard way that not all chemical products are good for plants. Perhaps a shrub you were trying to protect from pests is losing all its leaves after being sprayed.
There is a fact to face: not all plants can be saved.
Suppliers of chemical pest killers, herbicides and pesticides rarely provide the antidote to the poisons they manufacture.
However, try and contact the manufacturer customer service.
Sometimes they can share knowledge on how to reverse the effect of their products.
If there’s no known antidote, you’ll have to try to help your plant “ride it out”. You might even save it!
Removing excess product from the plant
If you sprayed the whole tree and it hasn’t rained yet, there might still be lots of product on leaves and bark.
You can wash it off with a hose.
Spread tarpaulins, an old watertight table protector, or even large trash bags split open under the tree, plant, or shrub. The goal is to capture the water or channel it to somewhere further off. This is to avoid seepage to the roots.
Hose the tree down abundantly to rinse off any product.
Some products are oily or oil-based.
To rinse these off, first spray a mix of soap and water.
Just a dollop of soap is enough (1 tablespoon for 1 gallon, or 1 teaspoon for a liter).
Then, rinse with normal water.
Removing contaminated soil
If most of the product was sprayed to the ground, you can remove most of the soil and replace it with fresh, clean soil.
Professional landscapers and gardeners sometimes perform air spading.
This is a technique where compressed air is blasted in the soil to loosen it up and blow it away.
Gather contaminated soil and dispose of it in an eco-center or waste disposal center.
Be sure to inform the staff of the type of pollutant so that they can guide you to the appropriate bin. It shouldn’t go to the compost or plant material bins!
Locking toxic compounds in Wood Charcoal
To try to cancel out the poison that’s already in the ground, you can grate wood charcoal. Wood charcoal has a tendency to absorb toxins. It will lock poison up in the ground and prevent it from entering the plant’s root system.
Which charcoal to use to save a poisoned tree
This only works with true charcoal, made from wood or plant material. Compacted pellets often used for barbecues won’t be effective here.
Use non-treated wood charcoal. Note that some barbecue charcoals have additives that lighting them up easier. Don’t use those as it might add to the poisoning.
It’s possible to “activate” your charcoal for an even higher chance of success. However, it’s a long process. It’s often easier to just use the charcoal directly.
How to prepare the charcoal
Grate it with a cheese grate or smash it with a mallet or hammer in a pouch (the leg of an old jean works well).
Sprinkle it on the ground, about a handful to a square foot (about the surface of a sheet of paper, or 30 by 30 cm).
After sprinkling, grab a rake that has strong, short teeth. Work the charcoal into the first inch or two of soil (3-5 cm).
Proceed carefully, trying not to damage roots.
It should absorb a large part of the toxins.
Over time, as the charcoal itself breaks down, the toxins will be degraded. The impact on the plant won’t be as severe.
Washing out the poison in the ground
Roots usually only colonize the first 6 to 12 inches of soil (15 to 30 cm). The goal is to wash toxins down to deeper levels. Bacteria and fungus can break them down without affecting the shrubs or trees.
Simply water the tree abundantly, soaking the soil down to a foot (30 cm).
Repeat after a week, and then again after a week. All in all, three soakings should be enough.
After thus rinsing the soil thrice, stop rinsing the soil out. Let it dry (to avoid root rot) and resume watering as normal.
How to treat a poisoned tree
Feed the tree with sugar water
Another technique is effective in helping trees recover from poisoning: sugar water. This provides a boost for the plant and feeds it. It isn’t the same as fertilizing as it doesn’t replenish nutrients, only energy.
Use a 1 and ¼ cups of sugar for one gallon of water. This translates to about 10 oz per gallon or 70g per liter.
Careful, don’t make it sweeter or the sugar will kill off beneficial bacteria and tiny animal life.
Use this mix to water under the tree.
For larger trees, make small holes 4-6 inches deep (10-15 cm) in the ground every couple feet (60 to 80 cm). Use a trowel or sharp stick. Then, pour the sugar water in the hole.
Repeat once a month during the growing season.
Best is to cover the area where roots are most active. This is usually marked by the drip line on trees that have never been pruned.
Tree roots commonly extend from the trunk up to twice as far as the tree canopy is wide.
For pruned trees and hedges, cover the ground within a 3 or 4 yard radius (3 or 4 meters).
Avoid high-nitrogen fertilizers
Refrain from providing high-nitrogen fertilizers.
High nitrogen levels in the ground will trigger the tree to make lots of leafage.
This is bad because the tree, instead of leafage, needs balanced growth to recover: roots, wood, etc. Nitrogen mostly triggers leaf growth.
Since the tree is weakened, the flush of activity on leaves will strain the tree and possibly kill it off.
The tree or shrub is trying to recover from the poisoning. You’ll have to give it time. Don’t wound the tree any further or subject it to too much stress:
Do not prune or trim the tree or shrub for a whole year.
Don’t remove any dead wood or branches until the following year. It may seem dead now but might revive after a while.
If it’s a low flower-bearing shrub, snip off the buds of at least half the flowers. This preserves the tree’s energy and helps it heal.
Also, protect the tree from other types of stress:
Watch soil moisture by scratching under the surface with your fingers. Avoid overwatering and underwatering.
Provide shade for your tree if it’s in a very hot spot. Use a shade net or place a square of cloth on stakes so that the tree or shrub is protected during the hottest hours of the day.
Lastly, don’t try to move or transplant your tree. This would result in transplant shock.
Smart tip about saving poisoned trees
If someone else is poisoning your tree, first find out who. Talk to them peacefully to learn why they’re trying to poison it, and work out what options might work. Sometimes a simple pruning is just what’s needed. Saving your tree will be impossible if someone else hopes for it to die!
You at should mention that intentional poisoning without owners concent, when fruit trees are concerned, the injesting of contaminated fruit from the tree, can result in long term serious life threatening deseases and cancers like those whom have been exposed to glysphosphate,that can result in serious criminal charges, like manslaughter or assault charges. Poison can persist for years and slowly kill off a tree, while tree still bears fruit, personal experience😥
REY Jean-Francois wrote on 18 November 2023 at 19 h 17 min
It is wrong to advise to cut branches that have been contaminated with round up because if you do the tree die from the extra stress you give to the tree from experience!!!
Trevor Jones wrote on 13 September 2023 at 12 h 14 min
Hi, How can I test to see if my trees have been poisoned ?
Gaspard wrote on 15 September 2023 at 3 h 11 min
Hello Trevor, I’m supposing you’ve already noticed symptoms of something strange happening, like leaves wilting and branches dying off.
There are quite a few diseases that can cause these, so try to look through those first.
Then, look for suspicious hints. Detective-style:
– is it the only tree impacted in the area? (helps rule out pests)
– are there holes drilled into the trunk? (clearly a sign of poisoning)
– empty containers, jug caps, that small foil that seals caps, etc? (possible that the poisoner has dropped them)
– previous hostility towards the tree, like neighbors constantly complaining or someone who clearly mentioned the tree ruined their view?
– traces of powder or chemicals
If any or several of these apply, there might be something to your suspicion.
In the end, though, only an expert can tell for sure, with testing for chemicals. You can bring slivers of bark, leaves, twigs to your local agricultural extension office (connected to state universities if you’re in the United States). Police offices might be able to direct you to the right laboratories if there are none in your area. Lastly, expert landscapers and garden store professionals can also take a look and give you their opinion on the situation.
Suzanne Williams wrote on 28 May 2023 at 16 h 48 min
Hi I was what would be best for a Tree that has been apparently accidently poisoned by my neighbour using Glysphosate it’s a large White Gum? The Leaves have all gone curly looking.
Gaspard wrote on 1 June 2023 at 3 h 04 min
Hi Suzanne, it’s going to be a challenge to save it, but it’s not impossible. A few key things to know:
– glyphosate will persist in soil for a month on average, but residues may last for a year. So it’s a long-haul battle.
– glyphosate will be transported to the growing tips of plants: root tips and branch tips (buds, leaves).
It kills plants by disrupting a basic cell-making function. Imagine gardening but the handles of every single tool are removed, and you can only work with oven mitts. That’s how it strangles plants.
To treat it, there are two things to do:
– as described in the article, try to remove the top layer of soil, around a foot or 30 cm deep. This is to get rid of any glyphosate that hasn’t yet been absorbed.
– second, since the material accumulates in leaf and branch tips, you can prune sickly portions off of the tree altogether. Dispose of these in the non-composting, non-recyclable bins so it can get burned.
Hopefully, some parts of the tree will be spared, especially if the glyphosate wasn’t spread evenly across the ground. This is because major roots feed only some of the branches, and there isn’t much sharing to the other branches. For instance, if the glyphosate was sprayed on the left of the tree, it’s likely that branches on the left side would be much more affected. You’ll have to cut these off, and hope that the right side of the tree can keep the whole tree alive for a while.
Cutting branches with new buds and leaves off will prevent the glyphosate that’s locked in there from returning back into the tree when leaves die off. The tree tries to salvage nutrients from dying parts of itself, and in this case you want to prevent that.
All in all it’s hard battle to fight, but if your tree can survive for 3-4 months, then it means the battle might be won. It’ll still be sickly and slow growing for a couple years, but then it should grow back fine.
Morgan wrote on 1 May 2023 at 22 h 11 min
It will help me with a large tree to identify the poison used. A white powdery residue remains on the lower trunk. Amy ideas on
1. The identity?
2. Where I can get the powder analysed?
Gaspard wrote on 12 May 2023 at 12 h 34 min
Hi Morgan, it’s really hard to tell because there are so many different types of poisons! If you were able to scoop some up, call your local agriculture extension office – they have the equipment and knowledge to look it up. Usually they’re connected to a public university, but in some cases it’s connected to the Parks and National parks division or to the chamber of commerce if there’s a forestry or agricultural division.
Donald G Riffe wrote on 19 July 2022 at 21 h 14 min
someone put poison at the base of my oak tree,how might I be able to save my tree
Gaspard wrote on 28 July 2022 at 5 h 53 min
Hi Donald, it depends how large your tree is. I suspect it must be pretty large already, otherwise why would someone have poisoned it? As it says at the end of the article: “If someone else is poisoning your tree, first find out who.” After all, anything you try won’t work if they just add more poison…
As to which techniques would work best, the one of air-spading to remove contaminated soil is the most effective, but it requires a professional who has the right equipment. Other than that, you can go ahead and try several of the suggestions listed in the article, or even all of them together.
Roots usually only colonize the first 6 to 12 inches of soil (15 to 30 cm). The goal is to wash toxins down to deeper levels. Bacteria and fungus can break them down without affecting the shrubs or trees.
You at should mention that intentional poisoning without owners concent, when fruit trees are concerned, the injesting of contaminated fruit from the tree, can result in long term serious life threatening deseases and cancers like those whom have been exposed to glysphosphate,that can result in serious criminal charges, like manslaughter or assault charges. Poison can persist for years and slowly kill off a tree, while tree still bears fruit, personal experience😥
It is wrong to advise to cut branches that have been contaminated with round up because if you do the tree die from the extra stress you give to the tree from experience!!!
Hi, How can I test to see if my trees have been poisoned ?
Hello Trevor, I’m supposing you’ve already noticed symptoms of something strange happening, like leaves wilting and branches dying off.
There are quite a few diseases that can cause these, so try to look through those first.
Then, look for suspicious hints. Detective-style:
– is it the only tree impacted in the area? (helps rule out pests)
– are there holes drilled into the trunk? (clearly a sign of poisoning)
– empty containers, jug caps, that small foil that seals caps, etc? (possible that the poisoner has dropped them)
– previous hostility towards the tree, like neighbors constantly complaining or someone who clearly mentioned the tree ruined their view?
– traces of powder or chemicals
If any or several of these apply, there might be something to your suspicion.
In the end, though, only an expert can tell for sure, with testing for chemicals. You can bring slivers of bark, leaves, twigs to your local agricultural extension office (connected to state universities if you’re in the United States). Police offices might be able to direct you to the right laboratories if there are none in your area. Lastly, expert landscapers and garden store professionals can also take a look and give you their opinion on the situation.
Hi I was what would be best for a Tree that has been apparently accidently poisoned by my neighbour using Glysphosate it’s a large White Gum? The Leaves have all gone curly looking.
Hi Suzanne, it’s going to be a challenge to save it, but it’s not impossible. A few key things to know:
– glyphosate will persist in soil for a month on average, but residues may last for a year. So it’s a long-haul battle.
– glyphosate will be transported to the growing tips of plants: root tips and branch tips (buds, leaves).
It kills plants by disrupting a basic cell-making function. Imagine gardening but the handles of every single tool are removed, and you can only work with oven mitts. That’s how it strangles plants.
To treat it, there are two things to do:
– as described in the article, try to remove the top layer of soil, around a foot or 30 cm deep. This is to get rid of any glyphosate that hasn’t yet been absorbed.
– second, since the material accumulates in leaf and branch tips, you can prune sickly portions off of the tree altogether. Dispose of these in the non-composting, non-recyclable bins so it can get burned.
Hopefully, some parts of the tree will be spared, especially if the glyphosate wasn’t spread evenly across the ground. This is because major roots feed only some of the branches, and there isn’t much sharing to the other branches. For instance, if the glyphosate was sprayed on the left of the tree, it’s likely that branches on the left side would be much more affected. You’ll have to cut these off, and hope that the right side of the tree can keep the whole tree alive for a while.
Cutting branches with new buds and leaves off will prevent the glyphosate that’s locked in there from returning back into the tree when leaves die off. The tree tries to salvage nutrients from dying parts of itself, and in this case you want to prevent that.
All in all it’s hard battle to fight, but if your tree can survive for 3-4 months, then it means the battle might be won. It’ll still be sickly and slow growing for a couple years, but then it should grow back fine.
It will help me with a large tree to identify the poison used. A white powdery residue remains on the lower trunk. Amy ideas on
1. The identity?
2. Where I can get the powder analysed?
Hi Morgan, it’s really hard to tell because there are so many different types of poisons! If you were able to scoop some up, call your local agriculture extension office – they have the equipment and knowledge to look it up. Usually they’re connected to a public university, but in some cases it’s connected to the Parks and National parks division or to the chamber of commerce if there’s a forestry or agricultural division.
someone put poison at the base of my oak tree,how might I be able to save my tree
Hi Donald, it depends how large your tree is. I suspect it must be pretty large already, otherwise why would someone have poisoned it? As it says at the end of the article: “If someone else is poisoning your tree, first find out who.” After all, anything you try won’t work if they just add more poison…
As to which techniques would work best, the one of air-spading to remove contaminated soil is the most effective, but it requires a professional who has the right equipment. Other than that, you can go ahead and try several of the suggestions listed in the article, or even all of them together.