Mold? Fungus? Not sure

Hi folks,

I've got a couple of plants and one of them recently has shown some strange growth.

Some details:

- growing outside, potted
- watering every 3 days (or at the mercy of nature, and it has been on the wet side)
- partial w/ an hour or so of full sun
- soil is a mix of triple mix and compost
- since flowering, I've been careful not to goose the soil with fertilizers

I'm posting two pics (sorry for the lack of focus). You can see that there is a white, powdery coating on the bud and surrounding leaves. This only affected one branch so I snipped it off.

Anyone know what this might be?



Appreciate any feedback.

could be anything, maybe powdery mildew, couild be something an insect or bugleft behind, could me mold or fungus, no real way to tel with thosepics, just not high enough qualityto make a good determination

looks like powdery mildew. in your growing conditions, on the wet side, it will be almost impossible to eradicate. u can try using 1 part milk to 10 parts water to spray on the plant, but the pm will return. if it's worth your time get some Serenade to spray on it as needed. that might get you through harvest. GL

have you done any foliar feeding?

Only a hour or so of full sun ??

If it is mold mildew more sun will help clear it up , just dont suddenly give them a full day at once

That is powdery mildew, and you are giving it IDEAL living conditions. PM thrives in low light, high humidity areas, especially if air circulation is limited.

Like others said, once you've got it, it's tough (but not impossible) to eradicate. Contrary to popular belief, powdery mildew is not "systemic" in the true sense of the word. It does pierce into plant cells to extract nutrients, but it DOES NOT flow through the xylem or phloem, and does not spread inside the plant. It spreads by producing an ungodly number of airborn spores, each of which is capable of infecting a new area of your plant.

At this point, your goal is to keep the infection contained and controlled. By preventing the fungus from fruiting (producing spores), you an limit it's spread. The best way Inhave found to control PM is potassium bicarbonate. Green Cure is the product I use if I see a little PM. Another hood product is Bi-Carb Old Fashioned Fungicide. They work well, but you need to be diligent and spray every 5 days or so until a week or so before harvest. If you wait longer than 5-7 days between sprays, new spots WILL show up, each producing a new pile of spores waiting to infect your plant. Use Green Cure at about 1/2 TBSP per gallon (half the recommended dose). Higher concentrations will cause leaf and/or pistil burning.

Good luck!

I just noticed there is quite a few in my garden.
I use a 6 inch fan in a 5X5 tent.
System is a Waterfarm so humidity stays high, from 45-68%.
I probably should use a dehumidifier especially because it is in 2nd week of flowering.

THAT, good sir, is a classic case of the dreaded powdery mildew. I copied and pasted something I wrote in another thread about my PM solution. Hope it helps.
I recently dealt with quite a large Powdery Mildew outbreak. I have it 99% handled now and it was fairly simple. Here is how I took care of it:
I have a hose that I have permanently run into my grow area. It has a little nozzle thing on the end I can use to temporarily shut it off and on while I'm working and the spigot is turned on. After the lights in the grow room turn off for the night, I go in there with a green flashlight and the hose turned on (fairly high pressure). I open up the nozzle just slightly so its spraying out a very small high pressure stream of water. I use the high pressure stream to spray off each leaf. You want it spraying fairly hard and you don't want it using tons of water, otherwise you'll end up with a massive mess all over the floor. So, you spray off all the leaves. Make sure the pressure isn't so high that you are snapping off branches and leaves. Spray off the plants as best as you can. It will make a bit of a mess on the floor, but you just use a towel to wipe that up afterwards. The next step is: hittin the girls with some neem oil. I use 2 to 4 teaspoons of neem oil extract/concentrate per liter of water. I bought "Garden Safe" brand neem extract from Lowes. I think it was less than 10 bucks. I'll include a pic along with other pics. I used to use stuff like AzaMax and/or Mighty Wash to control problems like spider mites. They were really hard on the plants and they were really expensive. Now that I'm using neem, I haven't had an issue in 6 months. I haven't seen a single spider mite, and it works fantastic for PM. No issues what-so-ever. I just hit the girls with neem once every few weeks, and my plants are happier and healthier than they've been in over 4 years. So, I use a "gun" that you can buy at Lowes that you use for painting... spraying paint onto walls. You can use any spraying device you want, but if you have a large garden, this investment will be worth every penny. I mix up my neem oil and spray away. You can do this a half hour or an hour after you rinse the girls off with plain water, but I usually wait until the next night, after they've had a chance to dry. You want to DRENCH the plants top to bottom with your neem oil mixture. I mean DRENCHED. You want the plants to look like there was just a rain storm in there for the last few hours or something. When you go into your grow room the next day, you'll see 90-100 percent of the PM gone (depending on how bad the case was). Repeat this whole process every 1 to 3 weeks as needed. Once you get rid of your powdery mildew, continue doing this every few weeks. It's called preventative maintenance and will save you so much heartache. If you are worried about tasting it on your bud, discontinue the program 2 weeks before harvest and rinse off with plain water one last time about a week before harvest. I'm telling you... If you do this and continue doing it as preventative maintenance, you will never have spider mites or PM ever again. It sounds crazy using moisture to get rid of a mildew substance. It's counter intuitive but it works. I swear to god. Lemme know how it worked for you. I will include some pics of some PM I found on my clones and used a small spray bottle to fix it. I din't use the plain water rinse first. I just went straight to a heavy dose of neem. Here's the before pics and the day after pics. By the way, I took the clones out from under the T5 fluorescent and just let them sit out in the middle of the basement for a few hours after spraying so they could dry without damage from the lights.

View attachment 2885380
If you look at the leaf in the middle of the left side, you will see some powdery mildew. It was actually worse than the pic shows, but I guess I took a bad pic.
View attachment 2885381
You can see I drenched these girls. I'd reccommend drenching them even more than this picture shows. Especially on big plants. you want them dripping wet. Sopping wet. DRENCH THEM.

View attachment 2885382
Here they are the next day. Nice and dry. Powdery Mildew free. Thanks to the magical Neem plant.

View attachment 2885384
Here's the neem I used. Its cheap and effective. I bought it at Lowe's hardware store, but I bet you can find it other places. There are tons of brands out there. This is just what I used. I've never tried any others, so I'm open to any other suggestions if you know a better brand.

View attachment 2885385
Here's a spray bottle with the neem oil mixture in it. There is about 250-300 milliliters of water and about 1/2 to 1 teaspoon of the neem concentrate in it. All concentrates are different, so always read the labels. Super interesting picture, huh?

I hope this helps. Lemme know how it went, if you try it. Feel free to ask me any questions, privately or in the forum.

if i were you i would do these following things to take care of this problem.


1. first you need to figure out why its happening, its most likely have to do with the growing conditions, it must be to wet, with high RH (humidity) so first you need to get that lowered ASAP and take care of it....even watering your plants less with lower RH in your room. you may be watering to much, just because the plant doesnt look so doesnt mean your not, so check that first

2nd you need to kill all remaining PW on your plants (powdery mildew) there are various ways to do this including and not limited to cutting off all infected leaves or buds if its bad enough BUT there are other ways to go about it, I will leave it to you to decide and research what you want to do and how you want to go about it

3rd you need to sanitize your grow room and kill all remaining spores/mildew not on the plants so they dont have a way or chance to spread. I would go about this by emptying the tent/grow area, take some water and bleach mixture, maybe a little soap as well...THOROUGHLY spray and CLEAN CLEAN CLEAN all the walls, floor, nook and cranny you can get into and make sure you do it RIGHT....do it TWICE if you have to....this is vital to you winning this battle, you MUST clean your grow room good or its just going to come back, clean all the pots that the plants are in as well...pretty much any surface in your area needs to be wiped and sanitized/cleaned.

lastly you need to make sure it doesnt come back. In order to do this you need to get either your relative humidity (RH) in check...how warm or cold it is in your room may be a factor as well, but wetness is really what you need to battle...the warmer the tent though the dryer it will be, naturally...I wish you the best of luck, if you have any questions, concerns or need any more help please feel free to send me a message or PM....Good luck friend

systhane or eagle (myclobutanil) works with 1 or 2 applications
myclobutanil is pretty much the industry standard fungicide used for PM
you can buy products containing this fungicide from regular garden stores
it is used widely on edible crops like grapes

peace