Imagine you've gone through all the trouble to create your first home grow set up, purchased seeds from your most reliable cannabis seed bank, grown a gorgeous crop of cannabis plants only to notice the whole thing has succumb to mould and bud rot. It happens…and quite commonly at that…which is why anyone interested in growing weed (or already doing so) needs to be aware of what to look for, what to do about it and most importantly of all, how to prevent it.


To spot the signs of mould or bud rot setting in can be the kind of thing that triggers blind panic and despair. The prospect of setting out to buy pot seeds and start again from scratch isn’t a pleasant one. On the plus side, it doesn’t always have to mean Armageddon for your plants – you just need to know what you are dealing with.

There are two mould types that are more likely to affect your plantation than any others – those being Botrytis (bud rot) and Powdery Mildew. They’re both pretty nasty to say the least, but present in quite different ways and with different effects.

Botrytis (Bud Rot)

Whatever you decide to call it, bud rot is simply the worst. The horror of seeing such treasure wasted away before your eyes is almost too much to bear. In terms of identifying the problem, prior to things getting really bad you might note discoloration or withering of the kola leaves. If you look closely, you might also pick up on white, green or grey fluff that starts to grow in and around the buds themselves. The result of bud rot is usually rotten, sludgy piles of nothing if the ambient humidity is high, or dried out, brittle and useless buds if the ambient humidity is low.

Powdery Mildew

It’s not difficult to see where this pest picked up its name – powdery mildew manifests in the form of what looks like a dusting of white powder. It first turns up on the leaves, only to eventually spread across the whole of the plant. It might border on the attractive, but this powdery layers make it difficult for the plant to go about its photosynthesis process, which means you’ll be watching your plant slowly starve to death. Leaves fade to yellow to brown and ultimately wilt and die.

Indoor and outdoor weed plants can find themselves stricken with both of these diseases – in both instances it is much easier to prevent them than to try and cure them.


These two conditions both enjoy the same kinds of environments and thrive on the same kinds of grower mistakes. With plenty of humidity, stagnant air and comparatively cool temperatures, there’s a strong chance you’ll be encountering one of the two in the future. Of course, there will be times when one or more of these conditions is impossible to avoid. The key therefore being to ensure that none are ever allowed to persist – certainly not when present in conjunction with one-another.


While it’s not to say that treatment is impossible, it’s more of a challenge and often proves largely unsuccessful. Still, hindsight can be a pain in the backside and if you’re already looking at a problem with disease, all that matters is dealing with it.

For bud rot, the only possibly-effective option is to arm yourself with a good biological disease control spray. The downsides of these kinds of treatments being obvious – plus the fact that while they might slow or halt the spread of the rot, they won’t cure it outright.

If it’s powdery mildew, it’s recommended that the diseased leaves be removed as soon as possible and the plant isolated in a dryer, warmer area. Use a good fungicide designed to work with mildew and you might get away with it.

Just be aware of the fact that in the case of both diseases, it’s inevitable that your final yield and its quality will be affected. Which is why you’ll need to ask yourself – would it be better to cull your infested plants and focus on the healthy specimens instead? Or buy marijuana seeds and start again from scratch? A tough call, but your call to make.

Here are a few tips and tricks to help avoid this disaster in the first place.

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