White powder kills leaves


Active Member
DSC00612.jpgi just wanted to know what that white powder is all over the leaves during flowering then kills the leaves .
answers would be greatly appreciated.



Well-Known Member
Can you take a close-up? It seems like some sort of pH shock or nutrient deficiency. So I guess I am bumping this for a more seasoned veteran to come along.


Well-Known Member
Powdery mildew is a common fungal disease that can seriously damage indoor and outdoor crops. Powdery mildew can rapidly infect crops in both vegetative and flowering stages, coating leaves, stems and buds in fungus.

Powdery mildew typically thrives in cool, damp, shaded and poorly ventilated areas. Airborne spores brought into the grow room land on leaf surfaces and will germinate given favorable conditions. High night humidity levels often trigger the growth of mildew spores. Powdery mildew can attack indoor crops year round.

Powdery mildew is almost impossible to stop in late flowering, so early detection and control is essential. Perpetual harvest, dense scrog/sog systems, and damp basement grows are particularly vulnerable to powdery mildew. Note: strains vary in their susceptibility.

This FAQ focuses on indoor prevention and treatment options. Please read Bongaloid’s Powdery Mildew FAQ for more information.

Identification, Symptoms and damage:
Early signs of powdery mildew include white powder/fuzzy patches on leaves (usually low in the canopy) and a fuzzy white coating on lower stems. Note: powdery mildew can be wiped off the leaves for a quick visual check.

(photo provided by turtle power) (photo provided by just one blunt)

These fuzzy mycelium patches produce airborne spores that rapidly attack adjacent plants; mildew will eventually coat leaves and entire plants, reducing photosynthesis, plant vigor and bud quality.

Plants on the edge of a garden, in corners and under stress are attacked first; infection usually starts in the lower canopy where conditions are optimal. As infection progresses, mildew will spread to the top of the plants and finally attack the buds.

Infected buds may appear normal; but are internally dusted with white powder (which cannot be removed by drying), and have a stale, musty/moldy smell when dry. Smoking or trimming infected buds can cause sickness and lung infections, and is not recommended. Infected leaves should be discarded. Lower buds are the most susceptible.

Powdery mildew is difficult to 100% eradicate; control requires prevention, early detection, and pro-active measures.

Preventive gardening:
Preventative gardening techniques can be effective in defending against powdery mildew.

Maintain healthy plants. Stressed plants are often attacked first, so it is important to monitor and remove unhealthy plants.

Detection. Inspect corners, edge and lower portions of the garden frequently. Remove infected leaves, or move infected plants out of the main garden.

Dont water plants at night. Reduce or stop watering before the lights have gone out to help evaporate and reduce room humidity (thnx dutchmaster).

Reduce plant density. Spread plants apart to improve air circulation. Don’t place plants directly against walls or into corners, typically areas of poor air circulation. Pull plants 6”-1’ away from walls or reflective surfaces, and blow air to these areas.

Pruning. Remove the lowest leaves as the plants mature and prune the bottom 1/3 of the plant during veg to increase airflow inside the lower canopy. Remove all unnecessary growth. Put an oscillating fan down low to blow through this pruned area.

Foliar feeding. Foliar feeding can sometimes cause excessive nighttime humidity levels. Discontinue if mildew appears.

Harvest early if mildew is a problem.


Well-Known Member
Thanks Mogie - the smaller pic was too difficult to tell whether it was the leaf or something on it. Wow.... first time I have seen or heard of this and something I need to be aware of because I am a basement grower possibly moving to sog.


Well-Known Member
i use a 100% solution of hydrogen peroxide to kill mildew on buds. i remove the whole plant from the garden and mist it down. seems to rid it of mildew present, new mildew will form though.
then it's time for the sulfur burner.


Well-Known Member
WoW, I had no idea how serious a problem that really is! I understand the statement referring to drying not being able to remove the mold and not to smoke it, but I was wondering if water curing his bud would wash the mold off and make the bud smokable?

Infected buds may appear normal; but are internally dusted with white powder (which cannot be removed by drying), and have a stale, musty/moldy smell when dry. Smoking or trimming infected buds can cause sickness and lung infections, and is not recommended. Infected leaves should be discarded. Lower buds are the most susceptible.


Active Member
wow ok my ph level is over 7 seven so im going to add sulphet ,
do guys think if i add a dehumidefire it would take care of my problem, or perhaps you guys have some other suggestions. i would really appreciat your help thx


Well-Known Member
Add ph down. If you don't have that go out and buy both ph down and ph up which are inclueded in your ph kit. A dehumidifier won't change your ph.


Active Member
the dehumidefire is for the mildew problem for the future will it help
and where can i get a ph kit
really appreciat this thank you.


Well-Known Member
Check home depot and lowes for the ph kit. If all else fails a hydro shop. A fungicide is cheaper and you can pick up Garden Safe at home depot for $4.99. Garden Safe has 3 different varieties. Fungicide is one of them. Can get the concentrate at Lowe's to refill the spray bottle and save big $$$.

Indica 1977

Active Member
So, if pH is in check b/t 5.8-6.3, humidity is b/t 35-45%, air is circulating like a mild wind storm, exhaust is leaving the building, clean air is entering the building, my DWC tote is all black, and I have soaked them in a peroxide (35%) solution, bleached out and changed out all hosing, and irrigation with fresh nutrient water is occurring ever 8-12 hours, and excess water is being drained from the resevoir, and the res water has been treated with a double-dose of SM-90, and hydroguard, why is it still there???? (The mildew).

We foliared today with a 2-5 solution of SM-90/water. I hope this also aids.

One more question: what happens if you can't get all the mites of your fruited plant and your fruited plant is telling you it's about time to cut it down? (less than one week out). Am I gonna get sick?


Active Member
im no expert but it looks like you got some kind of mold choking your buds b
bro. we get that alot here in washington its a killer. spider mites do that too! i have a few plants myself that arent doing well and im at a small loss as to whats goin on with them.. anyways thats my two cents but its probably nothin you didnt know already...peace


Uses the Rollitup profile
Staff member
I'm glad this was dug up, so indoor growers can read about how to avoid fungus. If fungus spores are able to grow on your plants, they will get a good grip, and when your buds start to ripen, the trichomes make for a perfect bed for new fungus growth, and the fungus will completely take over, and ruin your bud.

At first sign of fungus/mold/mildew treat with a good fungicide. Neem Oil is tried and true. Ed's new stuff Zero Tolerance is supposed to work, too. If you're able to use a sulfur vaporizer, that is the surest fungicide.

HTH :mrgreen:


Well-Known Member
I had the sulphur burner and sprayed everything with bleach water with every 7 days spraying safergro mildewcure top and bottom of plants as well as all parts of the room and after 9 months I have finally got a crop that is mildew free. Your stuff looks worse than mine ever did I wish you luck in ridding yourself of this nasty problem.Hitman40