HALP! Fungus attacking my houseplants!

[Aggie]

I've got some kind of fungus attacking my plants - this has showed up on a few in the past, but seems to be spreading.  It appears as white, powdery eruptions along the stem, and in some cases on the leaves or base of the leaves.  It seems to be going for woody plants more often than herbaceous ones or vines - took out a mango tree, is heavily infesting a jasmine plant, and looks like it's popping up on a dracaena.

It doesn't sound like powdery mildew or botrytis, but I've not had experience with either of these.  I'm isolating / destroying heavily impacted plants, and will lay off the watering and misting for a bit - any other tips or identification of said fungus would be appreciated. 

[Scriblerus the Philosophe]

What plants have you got?

[Aggie]

Lots: spider plants, pothos, Boston fern, rubber trees, several types of ivy, kangaroo vine, christmas cactus, a few different dracaena species, peace lillies, tradescantia (couple of species, I think), a few types of philodendron, china doll, coffee, kumquat, lipstick plant, weeping fig, a bunch of random trailing plants I've filched cuttings of, prayer plant, rau ram, spearmint, lemon balm, catnip, corsican mint, wild onions, tons of coleus, two kinds of palm, buddhist pine, persian sheild, monsterra, snake plant, jackfruit, sweetsop (I think, just came up), pitaya (couple varieties at the moment), holy basil and sacred tobacco.


Oh, and the jasmine and sugar vine that have been banished to the balcony until I sort out that fungus issue...

[Swatopluk]

Maybe you could try copper as a first line of defence (don't know whether that works on fungi too though)

[Scriblerus the Philosophe]

Lots: spider plants, pothos, Boston fern, rubber trees, several types of ivy, kangaroo vine, christmas cactus, a few different dracaena species, peace lillies, tradescantia (couple of species, I think), a few types of philodendron, china doll, coffee, kumquat, lipstick plant, weeping fig, a bunch of random trailing plants I've filched cuttings of, prayer plant, rau ram, spearmint, lemon balm, catnip, corsican mint, wild onions, tons of coleus, two kinds of palm, buddhist pine, persian sheild, monsterra, snake plant, jackfruit, sweetsop (I think, just came up), pitaya (couple varieties at the moment), holy basil and sacred tobacco.


Oh, and the jasmine and sugar vine that have been banished to the balcony until I sort out that fungus issue...

Good lord, man. So the jasmine and sugar vine are the ones with the fungus, yes? Any others?

[Aggie]

The sugar vine is probably OK - but it's sharing a pot with the jasmine and probably won't freak out from a bit of cold (might drop leaves, but should bounce back - if not, I run a Darwinist operation; divide or die ).  The jasmine's been looking a bit sick for a while, but I haven't been around much to check what was going on.

I think one of the dracaenas and maybe the prayer plant have minor fungus spots.  Already lost a mango tree (that was previously stunted & not in prime shape).

I put a fan on last night to up air circulation.  Everything seems to like a daily misting, but the high moisture has probably led to happy fungal conditions.  I will have to let things dry up for a while, particularly my large pots.  I've got an ongoing minor fungus gnat population, which is a good indicator that things are too moist.  I'm gone for long periods, so I tend to water heavily and not risk dry-out.

[Opsa]

Poor babies! You may try vinegar, as suggested here.

[Darlica]

Dry it out, when watering next time add nicotine extract, kills pretty much anything...

If I can I re-pot the plants in new soil after having washed all the old of the roots plus scrubbed the lower part of the stems as as much as it can be done without harming the plant and cleaned out the pots thoroughly with very hot water.

Soft-stemmed are harder to clean but on the other hand they regrow easier than hard-stemmed ones, but if it's a ? if they going to make it any way, I say clean, but that's partly because mould gives me a runny nose and headaches.

[Swatopluk]

As I said above a bit of copper might not hurt either (as an additive, not as main cure). Take a copper coin and treat it with a bit of strong (20%) acetic acid (vinegar may take a bit too long) in presence of air to get a bit of copper salt solution.

[Aggie]

Thanks for advice all, and apologies to Swato for a lack of timely response.  Sulphur is supposedly good as well.... how about copper sulphide? 

_{I don't have access to stronger acetic acid that I'm aware of - how about a copper nitrate solution? I have very small quantities of not particularly concentrated nitric acid available, and one would think the nitrates should be beneficial in small amounts.}

Still wondering - does anybody have any ideas of what this fungus is?  I suppose I should post pictures - not at home, currently.

[Swatopluk]

The sulphide is insoluble. Sulphate (or chloride) would do. 20% acetic acid is quite common over here ("Essigessenz") for both cleaning and food (after dilution). Be careful with nitrate, esp. if concentrated.

[Aggie]

Muriatic acid is probably available, but chlorides aren't good for plants.  Elemental sulphur is commonly used as a fungicide, even though it is insoluble (was joking about the copper sulphide, but while we're on the topic, which oxidation state of copper is propper?).

[Swatopluk]

Iirc all Cu(I) salts are insoluble, so Cu(II) would be the only option (elementary copper only as a source of salts*). Copper sulphate would be the most common apart from basic copper acetate that results from copper, acetic acid and air. Copper citrate is probably a bit too exotic (and it could also mask some of the copper as a complex).
Personally, I'd ask someone at the/a plant shop about your problem. They should have a basic knowledge on stuff like that.

*A common household tip is to put a copper coin in flower vases as a microbizide

Edit: http://en.wikipedia.org/wiki/Bordeaux_mixture

[Opsa]

The following info was lifted from this site.

Botrytis
Gray Mold, this fungus can be found many parts of a plant. Begonias, African Violets and Cyclamens are mostly attracted by this disorder.

To treat, cut away the affected parts and increase air circulation. Scoop away mold found on the soil, and spray the plant with a fungicide. Commercial versions can be found in any garden center. You can make a homemade spray first put water into a spray bottle, a tablespoon of baking soda, and a teaspoon of vegetable oil this may do the trick.

Black Leg
This horrible house plants common diseases disorder affects stem cuttings and is caused by a fungus called Botrytis. This fungus is found on cutting and turns the base black. Affected cuttings should be discarded. Prevention is simple.... have well drained soil and avoid over watering.

Powdery Mildew
Is found on the leaves of plants. It appears as a white powder on the leaves. Unlike Gray Mold, Powdery Mildew will not kill affected plants, but instead weak. To treat, removed badly mildewed leaves and spray the plant with a fungicide. Air circulation is the key for prevention.

Leaf Spot
This disease is most often found on Dracaenas and Dieffenbachia. I looks like moist brown spots on the leaves. In severe cases, the spots become one big spot and kill the entire leaf. Leaf Spot is caused by bacteria and fungi. Treatment is to remove affected leaves, spray with a fungicide, and water sparingly for a few weeks. Now house plants common diseases should be gone.

Watering is most important of healthy plants. Most tend to over water, creating the proper breeding grounds for fungi and other disease-causing agents. Always check the soil to see if watering is necessary by sticking your finger in the soil. If it's dry, add some water but if it's moist, leave it alone. Always make sure all houseplants have ventilation. Also don't crowd them. Always remove dead flowers and foliage as well.

[Aggie]

I am starting to suspect that what I'm dealing with is actually a major mealy-bug infestation, since it doesn't really fit any of the fungal descriptions and I can see mealy bugs on certain plants (they are at my sacred tobacco, so I doubt nicotine works as a control ).

Any advice?  I'm trying neem oil as a starter.

[Opsa]

That's probably a good way to get rid of them, provided you are careful to spray every surface.

Here is a good article on mealybug control.

[Aggie]

Thanks for the link, Ops. 

*grumble*

That's a lot of spraying, I've a lot of plants.  I'm trying to figure out whether I should keep using dish detergent as an emulsifier, or dissolve the oil in an alcohol base.  The latter will cause more damage to the mealies (and possibly the plants), but I have concerns about detergent buildup in the soil.

The first thing I'm going to do is haul off all the smaller plants to the shower for a spraydown to knock off as many mealies as possible.

This explains the spotty, sudden appearance of 'mold' in strange locations on various plants.  They are spreading quite quickly to new victims.  Hopefully I don't have to nuke the whole garden off - I don't likely have time to get this treated in the next week or two.

[Opsa]

Drag! I wonder if you can just get a tub of soapy water and just invert each plant and swish it out. Of course, that's a lot of labor, too.

[Aggie]

Given my penchant for pendulous vines, I think the spray will be easier.  Maybe I can neem 'em in the tub after a hosedown (allowing some drip-dry time first).  Neem is reputed to have some systemic effects, so a heavy enough dose to partially soak the soil might have some residual benefits - might help with fungus gnats too.