That is unusual because usually wicking will tend to extend how long your flowers last. So I have to ask, what are your humidity levels? Do you have a humidistat on your shelves? If not, you can pick one up at Home Depot for $9. It records temperature and humidity both and comes with a magnet to stick to steel shelving. Very likely wicking has raised your humidity and now it's getting warmer in the US with summer, the combination of warmth and humidity makes for fungal blooms not only on the plants but also to attack the soil and roots.

In this case, it sounds like your plants have powdery mildew. It usually shows up on leaves but it /can/ effect only the flowers. The reason is because there are many kinds of fungi that we loosely term 'powdery mildew'. If that is what is going on, you'd do well to remove open flowers, clean up and spray all of your plants, and thoroughly clean (with bleach water) everything else.

Increasing air flow (such as turning on a ceiling fan) can help but is more likely to spread the spores around more widely. What you really need is to add a systematic anti-fungal to your soil mix, or get and use a spray like Bayer Disease Control. The plant takes it up into the tissues and spreads it through the system to increase the plant's ability to resist fungal and bacterial attack. Unfortunately you'd need to reapply the spray lightly about every two weeks until temperatures drop back down in the autumn. /OR/ you can set up and run a dehumidifier in your plant area, or run the AC more. But either of those can get expensive.

Patty,

Thanks for such a detailed message. I did start a fan yesterday, so I hope it will help. Where do I buy the Bayer Disease Control? Lowe's or HD? I am going to get it today. I don't run my AC that much (kept at 80 degree), so the humidity is probably high these days. Rosie did suggest running a fan a while back, but I got lazy and hoped to get away without running it. Now I plan to keep it on.

Either may carry it but compare pricing online as you may be able to order it cheaper with free shipping. Yep, my temperatures are rather warm in my studio as well, even with AC so you and I have the same sorts of issues to contend with. You'll need to watch very closely for sudden root collapse but the Bayer will help with that also. I need to get more myself.

Patty,

I got the Bayer, but the instruction said apply no more than 3 times a year. Is it ok to apply every couple of weeks for a long period of time? Will it hurt the plants? How did you do to yours?

Hmm, I wonder if you have the same one. Bayer makes so many different but similar sounding products. The one I have says to apply every 2 weeks through summer. What exactly does yours look like or say?

Good idea with the disease control thing

Yes, that' looks like just the one I have as well though my label may be old. But it said clearly on mine 'Systemic protection lasts up to 2 weeks'

I don't have my bottle now as I used it up and took it to the dump but I have ordered another.

Yes, it did say it lasts two weeks. But it also says no more than 3 times a year. Since you used it through the summer, I guess it's ok to use more than 3 times.

Yes, I hadn't any problem but I only need it in high summer heat when it's also very wet. Once the humidity drops in later summer I don't need to use it. But for June and July? Yes. That's pretty heavy tropical storm season for us.

I'd actually prefer a soil treatment that is granular but the few I have found that are very well rated are also gastly expensive. I take a fresh look now and then to see what's out there.

Patty,

For granular, can you show me a link so I can at least look?

How about this one?

https://www.amazon.com/Revive-Organic-Soil-Treatment-Granules/dp/B001EEQ5RI

Hmmm, that's not really an anti-fungal at all. That's more of a slow release fertilizer. I was thinking of something more like Banrot actually. But it's very toxic and hideously expensive, though also very effective if used with caution. I don't use it myself but I know a lot of people who do (especially commercially) and they swear by it. I'm still looking around for a granular anti-fungal that I'd like to try without having to spend $100 or more for a 2 lb bag.

This one? This one did mention about mildew.

Toxic is not what I want to use inside the house.

Yes, I try very hard to avoid using anything that is highly toxic. There are usually much less toxic alternatives - and if not, then only use it out of doors, not in the home. I think that's wise.

This all in one product is also a fertilizer so that's not what I mean. But you are welcome to try it and see if it works for you. Over fertilizing however is a serious problem with gesneriads so I am wary of using products with ferts in them as I can't control that dosage when I need the granules for other reasons. So you'll have to use your best judgement whether or not you want to use a product that combines several things at once. I try to avoid them myself.

I'm currently looking at Copper Sulphate as a granule but it also comes in liquid forms. It is an anti-fungal that is also anti-bacterial, and is also good against snails, slugs, and algae. It is relatively non-toxic to us and quite safe to use in the home. It is however toxic to fish in high doses but is used in low doses in aquariums for an anti-parasitic. I could then be used as a spray on leaves and is used heavily for growing roses, grapes, and fruit trees as an anti-fungal, or can be applied as a soil drench, or used as a granule in a soil mix. One dose lasts about a month.

Thank you for the copper sulphate suggestion. I may try that if the Bayer spray doesn't work. I am going to save the name for future reference.

After doing some reading to be sure it is also safe to use on adeniums, I'm going to order some myself and see how I like it. As I also use sulfur based products for various things, I can't use oil based products like Neem oil, though I don't find Neem to be very useful against most things anyway. Sulfur + anything oil based causes phyto-toxicity so copper sulphate would be fine to add to my arsenal.