Pests and Disease Control
In the cases with all pests, prevention is always better then trying to rid an infestation. There are simple steps you can take to prevent infestations of most predatory insects.
The most affective IPM is a proper diet. Feeding your plants a nutrient rich diet, along with a healthy combination of beneficial microbes (bacteria and fungi) and silica which has been overlooked in the past but in recent years is becoming known more and more as a requirement in your plants diet.
Beneficial microbes encompass a whole variety of bacteria and fungus which have beneficial actions in the soil improving the overall health and quality of your crop. Pests and bacteria are sources of biotic stress which injure the plant reducing vigor, these stresses negatively affect growth development and overall yield. The addition to Bacillus and into the rhizosphere can be used to alleviate the stresses caused by these pests and diseases. Bacillus also produce endospores which help the bacteria survive harsh environmental conditions. It produces anti-microbial metabolites that can be used instead of synthetic chemicals for controlling plant diseases. Using Bacillus subtilis alongside silica can give it an extra boost against bad bacteria which degrades cell walls, limiting growth of your crop. Bacillus Subtilis can act as a biocontrol against pathogenic fungus and can be used to suppress the disease, or entirely prevent if it is colonized in the rhizosphere before an infection occurs. It’s ability to create biofilms on root surfaces and induce host systemic resistance which is how it prevents the fungal infection in the root zone. Bacillus Subtilis synergizes very well with Mycorrhizal fungi. The more diverse the population of beneficial microbes you have in your soil drastically increases these benefits, because bacteria compete for nutrients with the negative bacteria’s therefore the more beneficial bacteria inoculated in your root zone will prevent the buildup of negative bacteria.
Bacillus Thuringiensis is another very important bacteria that is fatal to different species of caterpillars, larvae, and maggots, as well as several other pests auch as fungus gnat larvae, you can find them on amazon called “mosquito dunks” or “bayers BT”.
Mycorrhizal fungi is another beneficial fungi that drastically speeds up root development, increases plant resistance to stress, accelerates plant growth, improves nutrient uptake, increases yield, reduces the amount of fertilizer needed, increases oil production and plant tolerance to salinity. Taking advantage of these benefits by combining them together in your plants diet will greatly increase your plants ability to fight off pets and diseases. There are many more strains of bacillus bacteria that have a wide range of benefits you can also take advantage of.
Neem oil on its own has been used for a long time, unfortunately (from what we have gathered from reliable online sources and now understand why certain neem oil products didn’t work for us) apparently all the neem oil available in canada, except the ones labeled “high azadirachtin content” are the left over oils AFTER the azadirachtin has been extracted from it for neem concentrated pesticides, rendering them ineffective against SOME pests. Because they cannot extract 100% of the azadirachtin the small amount in it is still poisonous to some pests, but not all. Neem has been used for thousands of years orally and topically for skin and hair benefits, however, now there is safety concerns regarding Azadirachtin poisoning when used as a foliar spray because of potential ingestion, but nothing has been confirmed as of yet. However, using it as a soil drench, or using neem cakes which have 2-4mg of azadirachtin per kernal are a safe and effective way to control pests. Keep in mind, neem is also a nematocidal which will kill off any beneficial nematodes. We like to mix the neem cakes in with our growing media prior to planting as it is not only a great pesticide but also contains micro and macro nutrients. Be sure NOT to use with seedlings as the NPK will burn your seedlings. Neem cakes are granules made from the neem tree seed residue. Its environmentally friendly as it is made from all parts of the neem tree. Neem cake is rich in nitrogen, phosphorus, sulfur, and calcium. This increases the nutrient content and fertility of your soil which increases growth and yield. These are totally organic which makes it suitable for all methods of gardening.
Planting some marigolds are always a good idea as they have a very potent aroma which will deter many pests including aphids; however, it attracts spider mites. The spider mites will flock to the marigolds rather than your cannabis, or other plants. Placing one at your doorway and a few around the grow room is plenty. They are low maintenance plants if you water it regularly.
If you haven’t used any IPM methods and are dealing with an infestation the best thing to do is put each plant carefully in a garbage bag and bring it to the shower if you have a removeable showerhead, or outside, hosing it off far from the house. Follow these steps for all the infested plants. Then if in veg proceed with the horticultural oil recipe every few days for two weeks. It is not recommended to use the oil recipe on flowering plants.
Using nematodes and beneficial mites are a superior IPM method that doesn’t involve spraying anything on your plants or any extra work. Neem will kill the nematodes, but will not effect any beneficial insects.
Nematodes there are a few different kinds of nematodes which are affective in killing fungus gnats, root aphids, soil mites, and other soil dwelling pests
Rover beetles are a great self reproducing beneficial insect that is best used as an IPM rather than once an infestation has started. They eat just about every soil dwelling pest including root aphids to an extent. (Sometimes the adults are too big for them to consume)
Stratiolaelaps Scimitus are a great predatory soil mite that helps control fungus gnats, thrips pupae, root weevils, spring tails and more. These are usually introduced at propagation to prevent fungus gnats infestations and thrips pupae for the life of the crop. These are readily available on Amazon, as well as many grow shops.
Neoseiulus Fallacis is one of the best foliar predatory mites preventing two spotted spider mites, bamboo mites, hemp russet mite, broad mites, and others. They can establish for many years after just one application because of there generalist diet. They are also capable of surviving on pollen when there is low prey.
Ladybugs are one of the most common beneficial insects as they love to prey on aphids which is one of the most common garden pests, they can eat up to 60 a day or 5000 during there entire lifetime. They will also eat other critters including white flies, weevils, and mites, however mites to ladybugs is like us eating bread crumbs for dinner, which makes them not very appetizing. A good way to keep ladybugs in your outdoor garden is by planting fennel nearby as these tend to attract ladybugs.
The praying mantis is another famous predatory insect. They will eat a variety of pests including but not limited too, aphids, flies, moths, and mosquitoes. Planting things like dill, fennel, and marigolds will help attract them into your garden.
Green lacewings are another good predatory insect that are especially helpful for controlling mealy bugs, as well as aphids. Again planting dill, fennel, cilantro, and sunflowers will naturally affect these green lacewings.
Beauveria bassiana is a fungus with spores that infect pests cuticle eventually growing and filling their insides with the fungus killing them and turns them into a gateway for spreading more spores, any insects that come into contact with the spores growing off of the dead insects will become infected and die. This is most beneficial when used as a preventative. If using for root aphids study’s prove you NEED to simultaneously add a neem extract high in azadirachtin. The azadirachtin is an anti-feedant, and anti-moltant(meaning it prevents the insect from molting/evolving into its next stage of life) which is essential since ROOTAPHIDS shed their cuticle each time they molt, so if they get infected there is a chance they will just shed that cuticle off, and molt into their next stage of life before it has time to infect them entirely. The combination of an azadirachtin extract of 3% or higher + Beauveria bassiana is the most effective way at controlling root aphids even once an infestation has begun.
Pyrethrum is actually a very useful pesticide, coming from the chrysanthemum flower, is toxic to beneficial insects and bees on contact and the residue can last up to 12 days, so not recommended to use outdoors where there will be bees present. It is organic (although there are synthetic pyrehtrins which we will touch on in a minute), it has low toxicity to humans, it doesn’t linger around, rapidly destroyed by UV rays, and isnt absorbed by plant roots. It is equally toxic to all pests, so don’t be fooled, on amazon the exact same raid product goes for 8.99 it is 0.25% pyrethrins, and means for flies and mosquitos 350g canister, and then they have 3 different bottles of the exact same ingredients 0.25% pyrethrins exact same weight of 350g for flying insects, multi bug, ant & spider which costs 12.49, at Canadian tire the same bottle different brand is 19.99. So do yourself a favor and actually look at the ingredients and make sure you’re not paying extra for the same stuff. This aerosol has saved our rear quite a few times, but if using directly on the plant it is best not to use an aerosol because you will burn the plant. You can get dr. doom powder and make your own spray, or they have spray concentrates you mix with water to make your own pyrethrin spray, these are better for using directly on your plant. And if using as a root drench the powder is probably your best bet.
Synthetic pyrehtrins are synthetic versions of pyrethrum. Some more toxic than others, some safter than others, some are longer lasting for example permerithrin is a synthetic pyrethroid and it lasts up to 60 days, it is recommended as a crack and crevice treatment to kill any pests passing through. I wouldn’t spray this on your plants tho, pyrethrum is much safer.
You can make home made pesticides from horticultural oils, there are many different kinds, however from our research food grade white mineral oil is the safest and most cost effective in 1 gallon jugs, it has been refined to remove as many of the unwanted petroleum additives as possible. From one gallon of white mineral oil, you can make 18 gallons of concentrate. Some people use sodium bicarbonate however, baking soda is phytotoxic, making potassium bicarbonate the better choice as it kills fungal spores on contact as well as pests and changes the ph of the surface of the leaf making it impossible for fungal spores to germinate. The only other ingredient besides water is pure castile soap, which is better then using regular dish soap. This spray can be used as a preventative all through the vegetative stage, however I do not recommend spraying it on flowering plants. The oil and the soap mixture suffocate the bugs. The oils block the air holes in which the insects breathe causing them to die from asphyxiation. Oils may also act as poisions by interacting with the insects’ fatty acids. Interfering with there metabolism. The oils also disrupt how an insect feeds a feature that is particularly important in the transmission of some of plant viruses spread by aphids. There toxic action is more physical than chemical and is short lived. Since these oil-based pesticides have low residual activity is must be sprayed directly on the insect, which is why a fogger is recommended. Avoid treating your plants drought stressed and under bright light because this can burn the foliage.
1 Cup/250 ML of horticultural oil
¼ Cup/60 ML of castile soap
1tsp of potassium bicarbonate
3475 ML of filtered/chlorine free water
Mix Oil, potassium, and water in a 4L jug, add the soap and shake well.
This is your concentrate. Do not spray this directly on the plants. It needs to be diluted to 15ML for every Litre of water. The white oil concentrate can be stored up to three months in a sealed container. When spraying be sure to spray with lights dimmed or off, and making sure to get the under side of the leaves as this is where most pests will lay their eggs, and where spider mites like to hang out. Also make sure your plants are well hydrated prior to application.
We recommend always spraying one leaf and waiting 6 hours before attempting to spray your entire crop. This works as a great preventative because it kills bug on contact and because of its oily residue and the potassium bicarbonate changing the ph of the leaf surface it kills powdery mildew spores and doesn’t allow spores to germinate on the leaves surface, you will need to apply this as necessary as it doesn’t last forever. Just not recommended in flower. Certain websites state it is fine however even after washing plants in multiple buckets there was oil residue in every bucket so we wouldn’t recommend it. Also using a paint sprayer in place of a fogger is super cost effective, its better to spend money on a paint sprayer and have it serve 2 functions than spend more on a fogger and only be able to fog with it. Corded ones pack the most punch in our experience.