Presumed recurrent fungal infection on Trident Maple

[Firstflush]

Maybe a long shot but any chances of herbicides wafting onto your property from a neighbors weedy fence line, adjacent commercial lot or even someone spraying driveway cracks? Checked pot drainage holes and dug around for soil grubs??

 

[Firstflush]

I have seen the herbicide thing really mess up orchards and roses when someone adjacent is spraying. Can be difficult to track down.

 

[Carol 83]

I have seen the herbicide thing really mess up orchards and roses when someone adjacent is spraying. Can be difficult to track down.

I work for a farm Co-op, and drift can be a problem. That's why they aren't allowed to spray when it's windy. Even so, we have paid for peoples gardens, etc. that were damaged, when spraying in the area.

 

[Firstflush]

I work for a farm Co-op, and drift can be a problem. That's why they aren't allowed to spray when it's windy. Even so, we have paid for peoples gardens, etc. that were damaged, when spraying in the area.

Had a customer get my take on legal action to recover costs for damage to his stone fruit orchard.

 

[Carol 83]

Had a customer get my take on legal action to recover costs for damage to his stone fruit orchard.

It happens, if they can prove who/what caused the damage.

 

[Lars Grimm]

Maybe a long shot but any chances of herbicides wafting onto your property from a neighbors weedy fence line, adjacent commercial lot or even someone spraying driveway cracks? Checked pot drainage holes and dug around for soil grubs??

Not a concern in my case for this issue, but I've definitely partially defoliated a chojubai accidentally by getting it caught in the downwind direction of fungicide.

 

[Lars Grimm]

Yes this is true. I don’t see it as helpful as most of the foliar treatments. Subdue is powerful nasty stuff and seems to be mostly used for pseudomonas and root problems. I’m at a loss to actually say which treatments have helped as it seems none have curtailed it.

Just gave my first root drench yesterday. All my tridents and japanese maples have begun to leaf out so I wanted to hit them when they are starting that strong initial push. Theoretically I could give another dose in 2-3 months, but I'll likely know before then whether it is working.

 

[ABCarve]

Just gave my first root drench yesterday. All my tridents and japanese maples have begun to leaf out so I wanted to hit them when they are starting that strong initial push. Theoretically I could give another dose in 2-3 months, but I'll likely know before then whether it is working.

I would do mine when the buds were starting to swell and just becoming active. Not saying you are wrong because I’m interested to see if it makes a difference. More heads working on the same problem can only help.

 

[Lars Grimm]

I would do mine when the buds were starting to swell and just becoming active. Not saying you are wrong because I’m interested to see if it makes a difference. More heads working on the same problem can only help.

That makes sense to me for a foliar spray, but for a systemic my thought process was to wait another week to allow more growth. I don't have any data to support this, but I assume the transpirative pull from the roots through the vasculature is greater when you have some foliar growth.

In reality, I treated all my japanese and trident maples. My kotohime are in full leaf, my regular japanese maples are just budding out, and my tridents are in between with some open leaves on part and some swelling buds on others.

 

[ABCarve]

That makes sense to me for a foliar spray, but for a systemic my thought process was to wait another week to allow more growth. I don't have any data to support this, but I assume the transpirative pull from the roots through the vasculature is greater when you have some foliar growth.

In reality, I treated all my japanese and trident maples. My kotohime are in full leaf, my regular japanese maples are just budding out, and my tridents are in between with some open leaves on part and some swelling buds on others.

If it makes any difference, I only have the problem with my trident. All others are sprayed prophylactically with copper and seems to work. I like your logic and hope it works. Please keep us updated.

 

[Lars Grimm]

If it makes any difference, I only have the problem with my trident. All others are sprayed prophylactically with copper and seems to work. I like your logic and hope it works. Please keep us updated.

My tridents also have only been infected, and only some of them. I do the japanese maples just in case (probably overkill).

 

[BonsaiMatt]

I am beginning to think that this issue is bacterial, caused by a root fungus Phytophthora and pythium. Ryan Niel mentions this in his 'Japanese maple fall structure' video, around the 55 min mark. His assessment aligns with the symptoms we are seeing: healthy spring push, then wilting etc when temps get hot in early summer. Root mold populations explode in the heat, and allow the bacteria to invade the plant (I forget the name of the bacteria, but it doesn't really matter). Of course Ryan says a balance of water and oxygen is the solution.

We all use fast draining soil, but in many cases with larger tridents, there are scars/rotting wood underground, and an area just under the trunk (Ryan's shin) that does not get rinsed with oxygenated water each day. I'm thinking that the area under the trunk gets depleted of oxygen, which leads to root mold, even in fast draining soils.

This theory is supported by a lot of the anecdotal evidence I have read in this thread, and what I have observed in my garden:

1. Topical fungicide sprays do not work because it's a bacterial issue in the shoots and fungal underground.

2. Dormant spray of lime sulphur does not work, I have noted this, and I think Lars has as well. Makes sense if it is a root mold leading to a bacterial infection.

3. Matt O. said to let trees grow past it, and be vigilant with water usage. Growing out will result in lots of root growth, possible healing of underground scars, and a healthier soil column overall. Not over watering should leave more oxygen in the soil and less opportunities for root mold.

4. Judy B. said to plant in the ground for a season. Similar to Matt O's plan, this would result in rapid root growth, healing underground scars and presumably leading to a healthier soil column when returning to pot culture.

5. Lars said he over waters because of his schedule, I do the same thing, and I see these same symptoms.

6. Symptoms appear during the first hot days of the year, making people think it's a watering/transpiration issue. This also happens to be ideal conditions for mold to grow in a hot pot.

So, I'm thinking we need to attack root mold. Even in fast draining high quality soil.

Possible treatments:
1. A hydrogen peroxide soak will help get oxygen to the shin.

2. Keeping the pot cool might help reduce blooms of mold in the heat of early summer.

3. Treating Phytophthora and pythium with a chemical approach, I'm trying azoxystrobin this year along with clearys 3336, might also try some mefenoxam, but it's expensive.

4. A biological application of mycelium + baccilus subtilus could dominate the soil, reducing the 'bad biome' bloom in the heat. I'm trying this approach as well (not the same tree as my chemical approach above). I'm most excited about this approach, no chemicals, no chance for the mold to build biological resistance to chemical treatment, just symbiosis and healthy pot culture.

5. A healthy, pristine root pad. Healthy roots will pump water out of the soil, maintaining a good oxygen balance.

It's important to note that the soil biome changes rapidly in the right conditions, so treating at the right time is key.

Questions:
Do your stricken maples have underground scars and possibly rotting wood? Mine do. Has anyone seen this on a tree with a 'pristine' root ball? As in with fibrous roots everywhere, even in the shin.

 

[ABCarve]

I am beginning to think that this issue is bacterial, caused by a root fungus Phytophthora and pythium. Ryan Niel mentions this in his 'Japanese maple fall structure' video, around the 55 min mark. His assessment aligns with the symptoms we are seeing: healthy spring push, then wilting etc when temps get hot in early summer. Root mold populations explode in the heat, and allow the bacteria to invade the plant (I forget the name of the bacteria, but it doesn't really matter). Of course Ryan says a balance of water and oxygen is the solution.

We all use fast draining soil, but in many cases with larger tridents, there are scars/rotting wood underground, and an area just under the trunk (Ryan's shin) that does not get rinsed with oxygenated water each day. I'm thinking that the area under the trunk gets depleted of oxygen, which leads to root mold, even in fast draining soils.

This theory is supported by a lot of the anecdotal evidence I have read in this thread, and what I have observed in my garden:

1. Topical fungicide sprays do not work because it's a bacterial issue in the shoots and fungal underground.

2. Dormant spray of lime sulphur does not work, I have noted this, and I think Lars has as well. Makes sense if it is a root mold leading to a bacterial infection.

3. Matt O. said to let trees grow past it, and be vigilant with water usage. Growing out will result in lots of root growth, possible healing of underground scars, and a healthier soil column overall. Not over watering should leave more oxygen in the soil and less opportunities for root mold.

4. Judy B. said to plant in the ground for a season. Similar to Matt O's plan, this would result in rapid root growth, healing underground scars and presumably leading to a healthier soil column when returning to pot culture.

5. Lars said he over waters because of his schedule, I do the same thing, and I see these same symptoms.

6. Symptoms appear during the first hot days of the year, making people think it's a watering/transpiration issue. This also happens to be ideal conditions for mold to grow in a hot pot.

So, I'm thinking we need to attack root mold. Even in fast draining high quality soil.

Possible treatments:
1. A hydrogen peroxide soak will help get oxygen to the shin.

2. Keeping the pot cool might help reduce blooms of mold in the heat of early summer.

3. Treating Phytophthora and pythium with a chemical approach, I'm trying azoxystrobin this year along with clearys 3336, might also try some mefenoxam, but it's expensive.

4. A biological application of mycelium + baccilus subtilus could dominate the soil, reducing the 'bad biome' bloom in the heat. I'm trying this approach as well (not the same tree as my chemical approach above). I'm most excited about this approach, no chemicals, no chance for the mold to build biological resistance to chemical treatment, just symbiosis and healthy pot culture.

5. A healthy, pristine root pad. Healthy roots will pump water out of the soil, maintaining a good oxygen balance.

It's important to note that the soil biome changes rapidly in the right conditions, so treating at the right time is key.

Questions:
Do your stricken maples have underground scars and possibly rotting wood? Mine do. Has anyone seen this on a tree with a 'pristine' root ball? As in with fibrous roots everywhere, even in the shin.

Look forward to seeing your results. Please keep us posted!

 

[Gustavo Martins]

I am beginning to think that this issue is bacterial, caused by a root fungus Phytophthora and pythium. Ryan Niel mentions this in his 'Japanese maple fall structure' video, around the 55 min mark. His assessment aligns with the symptoms we are seeing: healthy spring push, then wilting etc when temps get hot in early summer. Root mold populations explode in the heat, and allow the bacteria to invade the plant (I forget the name of the bacteria, but it doesn't really matter). Of course Ryan says a balance of water and oxygen is the solution.

We all use fast draining soil, but in many cases with larger tridents, there are scars/rotting wood underground, and an area just under the trunk (Ryan's shin) that does not get rinsed with oxygenated water each day. I'm thinking that the area under the trunk gets depleted of oxygen, which leads to root mold, even in fast draining soils.

This theory is supported by a lot of the anecdotal evidence I have read in this thread, and what I have observed in my garden:

1. Topical fungicide sprays do not work because it's a bacterial issue in the shoots and fungal underground.

2. Dormant spray of lime sulphur does not work, I have noted this, and I think Lars has as well. Makes sense if it is a root mold leading to a bacterial infection.

3. Matt O. said to let trees grow past it, and be vigilant with water usage. Growing out will result in lots of root growth, possible healing of underground scars, and a healthier soil column overall. Not over watering should leave more oxygen in the soil and less opportunities for root mold.

4. Judy B. said to plant in the ground for a season. Similar to Matt O's plan, this would result in rapid root growth, healing underground scars and presumably leading to a healthier soil column when returning to pot culture.

5. Lars said he over waters because of his schedule, I do the same thing, and I see these same symptoms.

6. Symptoms appear during the first hot days of the year, making people think it's a watering/transpiration issue. This also happens to be ideal conditions for mold to grow in a hot pot.

So, I'm thinking we need to attack root mold. Even in fast draining high quality soil.

Possible treatments:
1. A hydrogen peroxide soak will help get oxygen to the shin.

2. Keeping the pot cool might help reduce blooms of mold in the heat of early summer.

3. Treating Phytophthora and pythium with a chemical approach, I'm trying azoxystrobin this year along with clearys 3336, might also try some mefenoxam, but it's expensive.

4. A biological application of mycelium + baccilus subtilus could dominate the soil, reducing the 'bad biome' bloom in the heat. I'm trying this approach as well (not the same tree as my chemical approach above). I'm most excited about this approach, no chemicals, no chance for the mold to build biological resistance to chemical treatment, just symbiosis and healthy pot culture.

5. A healthy, pristine root pad. Healthy roots will pump water out of the soil, maintaining a good oxygen balance.

It's important to note that the soil biome changes rapidly in the right conditions, so treating at the right time is key.

Questions:
Do your stricken maples have underground scars and possibly rotting wood? Mine do. Has anyone seen this on a tree with a 'pristine' root ball? As in with fibrous roots everywhere, even in the shin.

Except that on mine and those in the video I posted, symptoms appear in spring when tridents are leading out. In summer they get better. So probably not the same?!

 

[BonsaiMatt]

Except that on mine and those in the video I posted, symptoms appear in spring when tridents are leading out. In summer they get better. So probably not the same?!

Interesting, I have not seen these issues on my trees until later in the growing season. Possibly a different pathogen.

 

[63pmp]

The original post has leaf blight, a bacterial infection from over feeding N. There are other things as well but hard to diagnose.

If you have free draining potting media than you cannot have root fungal infections, that simple really. If drainage is impeded by something, then yes it can be. The reason is because the main fungi that attack roots are partial anaerobes. They do not like oxygen and they don't like complete anoxia. They do need warmth, soil temps over 17 C if I remember correctly. They also need a period of days of low O levels before they can penetrate the root. So if you have good drainage you cannot have fungal infections in the roots.

pH with maples is super critical as a number of things happen. At high pH Roots cannot take up certain elements, at 6.5 and above phosphorus, molybdenum and boron become less soluble and so can be limiting.

At pH greater than 6.2 Nitrate starts becoming the dominant N form. This can cause Fe deficiency in maples.

Once soil pH starts going over 7 then Calcium can be bound up with bicarbonate at the root tip.

Depending on your water and problems present depends on what you see. Calcium deficiency is most dramatic with leaf curling and marginal necrosis. The others mostly yellowing of leafs and poor growth.

I've found J maples like soil pH of 4.5 to 5.5, 5.0 being best.

Hot weather exacerbates these effects because nitrification increases, water demand increases. Root tips are very sensitive to heat, so Calcium uptake drops off at higher temps (greater than 25C, I think)

 

[Lars Grimm]

I am beginning to think that this issue is bacterial, caused by a root fungus Phytophthora and pythium. Ryan Niel mentions this in his 'Japanese maple fall structure' video, around the 55 min mark. His assessment aligns with the symptoms we are seeing: healthy spring push, then wilting etc when temps get hot in early summer. Root mold populations explode in the heat, and allow the bacteria to invade the plant (I forget the name of the bacteria, but it doesn't really matter). Of course Ryan says a balance of water and oxygen is the solution.

We all use fast draining soil, but in many cases with larger tridents, there are scars/rotting wood underground, and an area just under the trunk (Ryan's shin) that does not get rinsed with oxygenated water each day. I'm thinking that the area under the trunk gets depleted of oxygen, which leads to root mold, even in fast draining soils.

This theory is supported by a lot of the anecdotal evidence I have read in this thread, and what I have observed in my garden:

1. Topical fungicide sprays do not work because it's a bacterial issue in the shoots and fungal underground.

2. Dormant spray of lime sulphur does not work, I have noted this, and I think Lars has as well. Makes sense if it is a root mold leading to a bacterial infection.

3. Matt O. said to let trees grow past it, and be vigilant with water usage. Growing out will result in lots of root growth, possible healing of underground scars, and a healthier soil column overall. Not over watering should leave more oxygen in the soil and less opportunities for root mold.

4. Judy B. said to plant in the ground for a season. Similar to Matt O's plan, this would result in rapid root growth, healing underground scars and presumably leading to a healthier soil column when returning to pot culture.

5. Lars said he over waters because of his schedule, I do the same thing, and I see these same symptoms.

6. Symptoms appear during the first hot days of the year, making people think it's a watering/transpiration issue. This also happens to be ideal conditions for mold to grow in a hot pot.

So, I'm thinking we need to attack root mold. Even in fast draining high quality soil.

Possible treatments:
1. A hydrogen peroxide soak will help get oxygen to the shin.

2. Keeping the pot cool might help reduce blooms of mold in the heat of early summer.

3. Treating Phytophthora and pythium with a chemical approach, I'm trying azoxystrobin this year along with clearys 3336, might also try some mefenoxam, but it's expensive.

4. A biological application of mycelium + baccilus subtilus could dominate the soil, reducing the 'bad biome' bloom in the heat. I'm trying this approach as well (not the same tree as my chemical approach above). I'm most excited about this approach, no chemicals, no chance for the mold to build biological resistance to chemical treatment, just symbiosis and healthy pot culture.

5. A healthy, pristine root pad. Healthy roots will pump water out of the soil, maintaining a good oxygen balance.

It's important to note that the soil biome changes rapidly in the right conditions, so treating at the right time is key.

Questions:
Do your stricken maples have underground scars and possibly rotting wood? Mine do. Has anyone seen this on a tree with a 'pristine' root ball? As in with fibrous roots everywhere, even in the shin.

Very interesting line of reasoning. I thought a lot about the Ryan video when I saw it. The idea of a good solid repot to fix the problem, just seemed too simple to me.

A couple initial thoughts:
1. I don't understand how a hydrogen peroxide soak would get oxygen to the shin.
2. Would a simpler option be to put plants on a tilt to maintain the balance of water and oxygen.

 

[BonsaiMatt]

Very interesting line of reasoning. I thought a lot about the Ryan video when I saw it. The idea of a good solid repot to fix the problem, just seemed too simple to me.

A couple initial thoughts:
1. I don't understand how a hydrogen peroxide soak would get oxygen to the shin.
2. Would a simpler option be to put plants on a tilt to maintain the balance of water and oxygen.

Just a theory, but a lot of things line up with it. I'm always the most hopeful in spring after thinking about solutions all winter, instead of looking at crispy maple leaves lol. I'm glad that people say that it doesn't seem to be fatal, but I'd really like to figure out a solution.

Hydrogen peroxide is H2O2, and breaks down into H2O and oxygen. A good soak (submerging the pot) will ensure it gets to the hard-to-reach shin. Never done it personally.

Tilting the pot could help for sure.

I'm curious how people water those over-the-top pancake nebari trees we all see from Japan. How does water not stagnate under the trunk?

 

[BonsaiMatt]

The original post has leaf blight, a bacterial infection from over feeding N. There are other things as well but hard to diagnose.

If you have free draining potting media than you cannot have root fungal infections, that simple really. If drainage is impeded by something, then yes it can be. The reason is because the main fungi that attack roots are partial anaerobes. They do not like oxygen and they don't like complete anoxia. They do need warmth, soil temps over 17 C if I remember correctly. They also need a period of days of low O levels before they can penetrate the root. So if you have good drainage you cannot have fungal infections in the roots.

pH with maples is super critical as a number of things happen. At high pH Roots cannot take up certain elements, at 6.5 and above phosphorus, molybdenum and boron become less soluble and so can be limiting.

At pH greater than 6.2 Nitrate starts becoming the dominant N form. This can cause Fe deficiency in maples.

Once soil pH starts going over 7 then Calcium can be bound up with bicarbonate at the root tip.

Depending on your water and problems present depends on what you see. Calcium deficiency is most dramatic with leaf curling and marginal necrosis. The others mostly yellowing of leafs and poor growth.

I've found J maples like soil pH of 4.5 to 5.5, 5.0 being best.

Hot weather exacerbates these effects because nitrification increases, water demand increases. Root tips are very sensitive to heat, so Calcium uptake drops off at higher temps (greater than 25C, I think)

Big assumption that you can't get root issues in free draining media. I have sworn by that mantra in the past as well, but what if we're wrong?

I have recently (middle of last summer) switched my water source from tap (ph 8) to a rain barrel. When it doesn't rain enough, I fill it with tap water and adjust the ph down to around 6ish. Hoping this helps nutrient uptake to maintain better health. I have seen chlorosis in some maple leaves in past years, hoping to eliminate that issue this year.

I am curious, how do you measure your soil ph?

 

[Gustavo Martins]

My water is super soft and I use free draining media. I may have calcium or magnesium deficiencies though. Will try adding some.