AusBonsai

My Leptospernum Petersonni, Lemon-scented Tea Tree suffered a sharp decline in health about a year ago, by autumn I decided a repot into a more free-draining mix might help, no fungus was visible at that time though significant root damage was evident. The repot halted its decline but it never regained proper health. I have now noticed this white growth underneath the pot (see photo) initially I thought it was mycorrhiza but now believe, upon describing it to a more experienced bonsai practitioner, that it is 'white root fungus' however I can't seem to find the exact product he suggested for treatment. Has anyone else had experience treating this?

Hi cre8ivbonsai,
If, it is white root rot, try Agri-fos or similar.

Also, I suggest a re-pot or at least allow air to enter around the soil to assist drying. Wash all tools & discard any soil into the bin. This rot will spread from contact to other soil.

Good luck,

Black Knight

Hi Ryan,

I agree with Black Night - additionally I'd put some spacers between your pot and the timber bench to improve the air circulation. Scrape of the fungus from your bench as well and disinfect the area - better still, replace the timber!

Good luck!

Cheers, Rudi

That is just wood rotting fungus living on the bench. It is completely harmless to roots (ie it won't attack living tissue) but it can cause a problem by smothering roots if there is a lot in the pot.(which is rare) Is there any actually in the pot? I have had plenty forming under pots on some of my old redgum benches and it has not caused any problems. (apart from rotting the bench!) Your root problem was not caused by this particular fungus. In fact, you can't actually see root rotting fungi with the naked eye.

BlackKnight even though Treeman's advise is reassuring, and the white fungus is probably not the cause of health decline but if it doesn't pick up in the next couple of weeks as spring kicks in, I think I'll still treat the tree with a round of systemic fungicide as it still could be fungal (just the invisible type). Thanks

Hi Rudi, yep, raising the black orchid pots to decrease the contact area should help, I've noticed it's started under another larger pot, but all the ceramic pots (with feet ) are fine! Might also clean/treat and flip the wood sleepers too.Thanks

Thanks Treeman, I guess a wetter (proper) Melb winter probably helped this stuff along with aging timber that has leached the last of its copper chromium arsenic protectant. You're right, it doesn't seem to be emanating from the pot, in fact there's some new roots peeking out the pot holes. Relieved it's not too nasty.

Thank you one and all

Ok so this is definitely emanating from the pot ...
This was from just 8 days on a 'clean' dry bench space

So while elevating the pot may stop it spreading, it is definitely contained in the pot, action is now required

While Agri-fos is recommended above, where can I get it? Or is there a bunn!ng$ alternative?

cre8ivbonsai wrote:Ok so this is definitely emanating from the pot ...

image.jpeg

This was from just 8 days on a 'clean' dry bench space

So while elevating the pot may stop it spreading, it is definitely contained in the pot, action is now required

While Agri-fos is recommended above, where can I get it? Or is there a bunn!ng$ alternative?

Did you have a look at the root ball to see whether the fungus is present in the pot? (Provided the roots have filled the pot enough, just pull it out and give it a gander).

Mo

Is there a possibility this is being over watered, or not getting enough sun? That is quite a dampened very greenish circular look for just 8 days compared with the wood outside the ring. I'd say you may have a drainage issue or all 3.

MoGanic wrote:Did you have a look at the root ball to see whether the fungus is present in the pot? (Provided the roots have filled the pot enough, just pull it out and give it a gander).

Mo

Thanks Mo, mix was quite loose last time I tried, but i'll try and have a geeze tonight ...

Rory wrote:Is there a possibility this is being over watered, or not getting enough sun? That is quite a dampened very greenish circular look for just 8 days compared with the wood outside the ring. I'd say you may have a drainage issue or all 3.

Hi Rory, position has been changed several times over the months, full sun to part shade, with no pick up in vitality, i'm not a heavy waterer, and the dampness is not green, just damp as the photo was taken soon after watering ...

I really just need to hit this with a dose of Systemic Fungicide, but just wanted to know from people which one might be the most effective and easy to obtain (having trouble finding Agri-fos ...

Ok, so this looks like the M@ster$ 'or similar' with (the same?) active ingredients ... https://www.masters.com.au/product/9000 ... cide-250ml

cre8ivbonsai wrote:

Ok so this is definitely emanating from the pot ...

Not eminating from the pot. The spores are everywhere all the time. On the bench, On your hose, on your hands and on your keypad right now looking up at you! They are just waiting for the moist environment under the pot to start doing what they do. If you're really worried about them, let the bench dry out a couple of days then paint it with some kind of wood preserver. (temporary fix)

treeman wrote:

cre8ivbonsai wrote:

Ok so this is definitely emanating from the pot ...

Not eminating from the pot. The spores are everywhere all the time. On the bench, On your hose, on your hands and on your keypad right now looking up at you! They are just waiting for the moist environment under the pot to start doing what they do. If you're really worried about them, let the bench dry out a couple of days then paint it with some kind of wood preserver. (temporary fix)

that is funny.

I lean towards agreeing with Treeman on this,... but let me explain why.

I had this exact same growth when I kept my bonsai on the back deck, which is just old wood. When you picked up the orchid pots and look underneath, most of the circular area looked exactly like your photo too. They would get part shade and they were all in orchid pots too.

However, now I keep all the orchid pots on pavers I bought from bunnings, and they are kept out in the garden. I have never seen the spores since moving them onto the pavers and out into the garden!

Rory wrote: that is funny.

Not really, taking the piss is just unhelpful.

treeman wrote: Not eminating from the pot. (temporary fix)

NO, emanating from the pot's contents, sorry if I confused you Treeman. Yes the spores then find a nice habitat under the pot as well ... (totally different bench btw)

Rory wrote: I have never seen the spores since moving them onto the pavers and out into the garden!

Maybe you should have checked those pot's contents? Probably still there ... are those trees healthy or struggling?

Moving the pot and doing nothing is why this tree is as unhealthy as it is, I'm not one for heavy handed chemical intervention, but when a fix is required so be it.

I was just trying to get advice about SYSTEMIC FUNGICIDE treatments as they all seem to have differing active ingredients. Now that I've found one close to the only recommendation in this thread, thanks Black Knight, I'll get on with it!

MoGanic wrote: Did you have a look at the root ball to see whether the fungus is present in the pot? (Provided the roots have filled the pot enough, just pull it out and give it a gander).

Yep finally got a quick look this morning, and there is white fungus throughout, which appears to have stopped the roots growing and filling out the pot (lots of loose mix, esp at the bottom). At least there is some small amount of new root growth. I'll inspect further once i get the SYSTEMIC FUNGICIDE, treat and repot. Thank Mo.

cre8ivbonsai wrote:

Rory wrote: that is funny.

Not really, taking the piss is just unhelpful.

He wasn't taking the piss. He just has a humorous way of talking, as what he said was true, and I found it humorous

cre8ivbonsai wrote:

Rory wrote: I have never seen the spores since moving them onto the pavers and out into the garden!

Maybe you should have checked those pot's contents? Probably still there ... are those trees healthy or struggling?

Moving the pot and doing nothing is why this tree is as unhealthy as it is, I'm not one for heavy handed chemical intervention, but when a fix is required so be it.

No, all trees' health improved remarkably once I moved them to an area of more sun. I also added a lot of drainage (rocks) to the medium and they have literally shot, (taken off). What I would strongly recommend is, that considering this is a very nice piece of stock you have, taking your tree to a bonsai nursery and asking for advice there from an expert, or if you are not in drive distance, take it to a normal nursery and show them the tree with the soil and the problematic contents you are referring to.

Good luck. A lot of fungus can get worse from shade and excess moisture, but I would see a horticulturist or specialist nurseryman in person if I were you. I have done this before with problems I have had from fungus in the past and this was their advice, which worked.