Note: For technical assistance with any of our courses or lessons, please contact chris@growersnetwork.org

Lesson Summary:

In this lesson, Jack presents a few pest and general problems you may run into with your grow.

Lesson Transcript:

Hello, I’m back and in this video I’m going to throw some problems at you.

If you’re growing Cannabis, their will be some problems. It’s important that you look at your plants every day and most problems happen because of fertilizer being given incorrectly. For example: the tips of your leaves turn yellowish and become crispy. That means you gave a bit too much fertilizer. Just stop giving fertilizer, and just give them pure water for a while.

Another problem that happens often, the leaves turn yellowish and they don’t look as healthy anymore. Most of the time that’s a calcium or magnesium deficiency which means you would give them something called Cal-Mag. This is another supplement and it will likely fix it. But keep in mind, all the leaves that are yellowish and don’t look nice, they will not turn green again, they will remain yellow. Only look at the new growth coming out. The new growth coming out must be green and nice and healthy.

These are brown dead areas in the buds. This is bud rot, meaning mold. This happens when humidity is high and the buds are big and dense. This is a toxic gray mold, and it will spread over your plants like a wildfire. Even cutting out the affected areas likely won’t stop it because the mold spores fly like dust all over the plants. You need to harvest this and save the unaffected areas or you lose it all. Don’t consume any of this moldy stuff, or you’ll get sick.

On this plant the leaves have dropped and the whole plant looks sad. This probably means the plant is totally dried out and needs water. Just give it a good drink of water and it will take just 10 minutes and the leaves should be up again.

This plant is tiny and it doesn’t grow. There can be many reasons for this. Does it have enough water? What soil are you using? It would be best for you to head over into our user forum at Growersnetwork.org and just post a photo of your plant. Then we can have a look and help you out.

This plant here is totally thin and weak and about to fall over. In this case you need a better light or get more direct sunlight. Just go and buy a good grow light.

The next set of problems you will encounter are pests, and that means little bugs that enter your grow room. This plant has little white spots all over the leaves. Also you can see some of these spiderweb like webs over it. These are spider mites. It’s a very common pest. You’ll need to treat this immediately with a mild pesticide. If you don’t treat this right away, those spider mites will take over your whole plant and ruin it, but you can spray it with a good pesticide and you’ll get rid of them.

Those were a lot of problems right? I will now show you how you treat them and how to make it right.

I’m using this stuff here, this is a mild pesticide you can use this stuff for plants that are grown for human consumption. Of course we’re going to consume this cannabis later, so we shouldn’t use too strong of a pesticide on them. And here’s how to use it: Make sure you use this in the darkness because if the lights are on, there will be water droplets forming on the leaves and they’ll act like a magnifying glass, putting burn marks on the leaves. So once the lights are off take out your plants and spray them generously with this pesticide, really drench the whole plant. Make sure you also hit the underside of the leaves because that’s where those critters hide. Eventually the whole plant should be drenched. Now let it dry. You’ll need to do this more than once, so tomorrow evening you do it again, and the next day you do it again. So altogether, you do it three times just to make sure the spider mites or whatever is on your plant is actually dead.

And that’s how you treat your plants, and I hope to see you in the next video.

Course Notes

Recommended Reading:
How to Grow Cannabis 219 – Integrated Pest Management
The Wrong Way to Use Chemical Pesticides
Growers Network’s Disease Profile: Bud Rot
Growers Network’s Disease Profile: Powdery Mildew
Growers Network’s Pest Profile: Spider Mites
Growers Network’s Condition Profile: Nutrient Burn

Suggested Products

Enter code GNU-Student for 10% at Growershouse.
(Excludes “Killer Deal” items)
True North Seed Bank
Grow Tent Configurator
HLG 500w Quantum Boards
Quantum Board
Fluence Spyder
Ocean Forest Potting Mix
FloraNova Grow
FloraNova Bloom
pH Up
pH Down
Hanna pH Tester
HM Digital Waterproof Combo Meter
Radix Plant Rooting Compound
Fan
Air Filter
Fan Speed Controller
Timer Switch
Fabric Pots
Mini Germination Greenhouse
Five Gallon Bucket
Glass Curing Jars
Humidity Packs
Scissors
Thermometer/Hygrometer
Grower’s Edge Illuminated Microscope 60x – 100x
Watering Can
AzaMax Biological Insecticide, Miticide, and Nematicide

Want to discuss this lecture with your fellow students? Click here!