How does fungus spread? and Sanitizing after fungus battle..

Hi All, I have spent the last week waging war against fungus on my 3 treasured tropical hibiscus trees. Now that i've taken all the steps I can think of to eradicate it from the soil, etc., what do I need to do to prevent its' spreading to other plants? In fact, how DOES a fungus spread between plants? I don't recall having used any common tools on my three (except my hands?!), and they weren't close to each other before this headache appeared.
So anyway, I have washed the poor plants' roots, bagged up & disposed of the offending soil, and washed my tools and pots with bleach (pant, pant). My driveway was where all of this carnage took place; do I need to wash IT down w/ bleach solution? (there is still some residual soil on the drive, and some surrounding stones). I want this invisible creature to be gone for good! I have that contaminated feeling myself, as if I'm the carrier or something. I wear disposable gloves and change them often, trying not to cross-contaminate, but I don't know enough about fungi to say whether I've made mistakes. Anybody??? Thanks, as always, Polly

Well Polly, you aren't going to like this answer, but a lot of the fungus are spread thru the airthey are spores that are easily carried in the wind etc. The spores of pythium and phytopthera are spread from even the mildest of watering from one pot to the next, and of course from the bottom of shoes and tools that were in the dirt that had the fungus. Yes you should wash down the driveway with bleach -you can take a bucket and pour some bleach in it ( 3:10 ratio of bleach to water) and water and pour it over the dirt. Bleach solutions are only good for 2 hrs, and then the bleach begins to break down.

I don't know what fungus you had, but it would be a good idea to apply a systemic fungicide to the soil of the hibiscus after you repot it. I can't tell you what fungicide to use w/out know what the fungus was...do you know? I would also keep these hibiscus far away from all other plants until you know if what you did ( washing the roots-hopefully with a hydrogen perioxide solution-or soaking them in it) worked. Good luck-its a real pain in the butt, I know!

Tigerlily, Thanks so much for the info. This whole process has been a real challenge, especially in terms of learning what to do at each phase of the game. I haven't a clue which fungus we have amung-us, nor how to find out. I did NOT use peroxide on roots - didn't know to - aaarghh : ( , but I did apply a systemic... by Bayer, I believe.

The foliage is looking extremely healthy, but the bark is compromised on all three, and very badly on the oldest one. Large cankers all over the poor thing. I've heard varying things there, too - should I attempt to cut out the wounds (some bigger than a quarter), or let the plant try to repair itself?! If I cut away the damage, the wounds in some places would be nearly half the mass of the stem//trunk. I can't tell whether they've gotten any better or worse since their repotting. Sigh.

I sure do love DG though, and can't thank you enough. No sooner had I joined than my trees fell ill....these things happen for a reason, eh?! Polly

Well Polly, cankers on hibiscus trunks...this is out of my realm of expertise...I grow annuls for a living, and so I can tell you about what fungus effect what annuals and how the fungus presents on the plant, but I don;t grow hibiscus for a living and have not had this problem. However it should be pretty easy to find out what the problem is by googling the systems /hibiscus and identifying the exact problem, and how to treat it. Are you sure its a fungus and not a pest problem?

Tigerlily, In fact, I think that my problem is both fungus AND pests... But I have no certainty that I'm right... I have spent tons of time looking for the type of wound I'm finding on my stems, without success. Trying to get a picture to post in case someone recognizes it. The fungus gnats are what convinced me that it's fungus, plus circumstances leading up to the appearance of symptoms. Also, much of the root ball is brown - about half, I'd say.
They had what may have been aphid casts or scale first, then the fungus thing. Not sure what caused what. Mysteriously, the foliage still appears unscathed and looks quite happy. One of the three is flowering. I think my next step needs to be posting a picture of the stem cankers, (if that's really what they are!)
I'm hoping I might be able to ID the fungus (I've grown to really hate that word...!) , so I'm not just making stabs in the dark!
Wishing you a fungus-free existence! I really am very grateful for your fedback. Polly

Polly,

I checked my book "Pests of Landscape Trees and Shrubs", and the only thing listed that caused cankers on the stem for Hibiscus was Armillaria root rot (AKA oak root fungus). This book was written by University of CA so there may be other things in other parts of the country that could cause it too and they wouldn't list them. I'm not really sure that's it because the book said usually the leaves will show symptoms first, and you said yours are fine, and I also tend to think of this fungus as one that lives in garden soil as opposed to pots and typically would only spread to other plants that are planted in or near the contaminated soil. But if that is what is causing it, the book said it thrives on warm wet conditions, and also that it can live in the soil and roots for quite a long time, so you're going to have to be on the lookout for it coming back even if you manage to get rid of it this time. They are focused on integrated pest management, so they only suggest cultural things like proper irrigation and not planting something else that's susceptible to that fungus in the same spot where it killed something previously, but if you check on the internet you might find some suggestions for chemicals that would help.

Thank you, Ecrane, for taking the time to research this on my behalf. DG people REALLY have impressed me as being enormously helpful and knowledgeable. Wow! What a gift!

I'll investigate Armillaria, and hope shortly to post a photo of the wounds to better illustrate what's happening with the stems. I know that only certain fungicides work on specific fungi, so I assume I need to properly ID it to have any hope of vanquishing this beast. I've read that plants can seem okay with fungus and then just suddenly wilt and die without warning, so I'm not feeling overly encouraged by the healthy foliage, either.

Perhaps I'll have a big breakthrough soon and will triumphantly post my good news....hmm - maybe! Again, many thanks! Polly

fungus gnats don't neccessarily mean that there is a fungus-just that you have an environment suitable for the gnats. Wet soil where there is some shade ( from the foliage of the plant ect) Fungus gnats can carry and spread a fungus, but its not always the case. The roots being dark would possibly suggest a root rot fungus ( pythium or phytopthera are the most common and are treated by the same fungicide-that does not work on any other type of fungus) Depending on where the cankers are on the plant, if near the soil line, it could be pythopthera-which acts like it girdles the stem and cuts off supply of water -but you would see it in the foliage.Vinca gets a classic case of phytopthera and the stem appearing to be girdled-sometimes it only affects half the plant.

Plants that seem ok and then suddenly wilt and die are usually from really high soluble salt build up-an intense amt. The roots are totally burned from too much fert. A lesser amt of fert that only slightly burns the roots will present as brown edges on the leaves-leaching the soil several times will save those plants.

Just kind of throwing info at you to see if anything applies...:)

I still think it's really weird that your leaves are showing no symptoms, plus I'm sure you had these in potting mix and those types of fungi like Phytophthora, Armillaria, etc tend to be found more often in garden soil, so as I think about it more I start to wonder if it isn't something else other than a fungus. I wonder if there is such a thing as a Hibiscus borer?

If it is one of the soil fungi, the best way to keep it in check (assuming the plants recover from this initial attack) is to be very careful not to water too much--the excess moisture is what triggers these fungi to grow. Many times they can be in the soil and have no effect on the plant at all as long as the moisture level is good, but then you overwater slightly and poof, all of a sudden there's a fungus problem. I lost a nice Toyon tree at my old house to Phytophthora...it had been growing nicely for years even before I moved there, then I ripped out the ivy that was there and put in real plants, and of course had to water them to get them established, and all of a sudden the leaves started dying on one branch at a time, finally enough of the branches were dead that I had to cut it down. It got cankers on the trunk too, but I noticed the branch dieback way before I noticed anything on the trunk.