I’ve had a few successful indoor growing ventures, but this time my marijuana garden has been infested with mealy bugs. I’ve changed the soil, used pyrethrins, predators, Safer’s soap, and Malathion. I’ve only had success killing the bugs with Malathion, but it also severely damages the plants. Do I have any recourse here?
Mealy bugs are white, covered in a cotton-like web, and are about 1/8-inch to 1/4-inch long. They reproduce quite slowly (a cycle lasts just under a month). Because of this, mealy bugs rarely cause a threat for the short-lived, fast-growing cannabis plant. If you have only a few bugs, then you can simply wipe them off with a sponge or a Q-tip or you can just cut the branch off. You can also spray groups with a 25% alcohol solution and then wipe off the leaf with a sponge.
More intense infestations require treatment in stages. Make a spray that combines diluted neem oil with an herbal tea that has 1 tablespoon each of mixed Italian seasoning, ground cinnamon and cloves, four large cloves of fresh crushed garlic, and 8 ounces of denatured alcohol. You want a quart of this mixture, so add some water when finished.
Boil the water. Put the water in a blender with every ingredient aside from the oil and the alcohol. Blend everything up and let it sit for half an hour. Add in the horticultural oil and alcohol as instructed. Mix it in and strain, and then use it as a dip or spray once every 3 days. Using this method will eliminate the bugs eventually and will immediately reduce their population so the plants aren’t harmed as much.
The marijuana plants need to be clean to ensure that the infestation doesn’t make its way to the new plants. Cannabis clones need to be thoroughly cleaned first. In fact, the clone area needs to be quarantined and kept very clean. To do this, wipe down the room with detergent, and let it air out thoroughly. After that, provide the room with a second wipe down with a 1% hydrogen peroxide solution. This will eliminate anything that might be hanging around. The garden will be free of bugs at this juncture.
Because insects don’t just materialize out of thin air, they had to have invaded from elsewhere. Look for cracks and openings to discern where they might have come in. You should also create a protocol for safety and cleanliness (i.e. changing clothes from outside so that you don’t carry insects inside). It’s not uncommon for people to brush up against a bush or a tree, pick up a pest, and then bring it into the indoor marijuana garden.
Robert