Benjamin Franklin’s “an ounce of prevention is worth a pound of cure” really pays off when it comes to pest management.
Growing Cannabis indoors provides excellent conditions and abundant food for pests. Protocols need to be set up for reducing invasions by these outdoor monsters. Once you let them in it can be very difficult to get them out. Be concerned with the damage done by feeding, as well as the potential havoc of a virus or disease introduced to your plants.
The most common invaders are fungus gnats, whiteflies and spider mites. Their life cycles are affected by temperature – the warmer the environment, the quicker the life cycles and the faster they will reproduce. Indoor environments lack the natural predators that keep these pests under control. Unchecked, infestations can develop rapidly, becoming severe and chronic problems. Many gardens have been destroyed by infestations getting out of control – especially during flowering. Early detection and diagnosis are as important as choice and application of treatments. Using multiple tactics to affect insects in all stages of their life cycles is a more effective strategy than relying on one solution. These are the principles of ‘Integrated Pest Management’ (IPM).
Fungus gnats (small, dark fly-like insects) are a small nuisance when compared to other intruders. Gnats love moist conditions; do not be surprised when you get one up your nose if they invade your garden. Gnats are encouraged by over-watering, so letting your soil dry out properly and eliminating any standing water will discourage them from developing into a problem in the first place.
A fungus gnat’s life cycle consists of four stages: egg, larva, pupa and adult. The larval stage is the most damaging to plants. It is during this part of their life when they feed upon the tender roots of plants. They are harmful to sprouts and clones as they are establishing new root systems. Damage at this early stage of life can affect yield later on, although plants often outgrow it.
Even more catastrophic are the few hitchhikers fungus gnats can bring with them. Pythium, a water mold, does not seem scary until the fourth day – when all your plants die! For a commercial greenhouse with several thousand plants hooked into the same hydroponic system this would be disastrous.
There’s no guaranteed safety in soil, either. Phytophthora, another of the gnats’ buddies, is a terrestrial kind of water mold. This insidious parasite was responsible for the Great Irish Famine, causing over one million deaths. Fusarium is a species of fungus that likes to ride along with gnats. A few of these species cause crop damage in the billions, but most are harmless. Fusarium oxysporum, often called the Panama Disease, wiped Gros Michel bananas (known as ‘Big Mikes’) off the commercial market in the 1950s.
An oscillating fan not only helps dry out topsoil, but it also makes it difficult for those buggers to fly around. Some friends have had great success spraying soil- or hydro systems with a dilution of Dr. Bronner’s Peppermint Soap and water. Others have used a dilution of hydrogen peroxide and water. Whichever method you choose, make sure your concentrations are not strong enough to damage the plants. Yellow sticky traps, commercial or homemade, are also a great non-toxic method for enticing and trapping these pests. The easy way to deal with a fungus gnat infestation in containers is by putting an inch of sand on top of your soil – this will prevent them from laying eggs.
Whiteflies are a more serious invader. Small, white moth-like creatures, they wreak damage by sucking out life fluids like small vegetarian vampires. If these bugs get in, they may bring a few of their over sixty viral plant disease friends with them. Then, as an extra insult, their excretions promote the growth of mold – and who would want to smoke or eat any of that?
Whiteflies lay eggs on the underside of leaves. Within a week the eggs hatch and the larvae find a nice spot to suck from. The next week-and-a-half is spent in various nymph forms until the final metamorphosis into a flying adult – when they become easier to spot. A little shaking of the plants sends them flying around the room. Oscillating fans, combined with yellow sticky traps in each planter and around the grow space, can help prevent them from achieving a foothold. Whiteflies are drawn to the yellow traps, making you aware of their presence in the grow room.
If whiteflies are established yellow traps are not enough to get rid of them. A few small plants are easy to manage by physically removing eggs and vigorously spraying the underside of the leaves with a dilution of Dr. Bronner’s Soap, daily. Large plants or lots of small plants can be difficult to manage.
Wasps can play a good part in prevention and control of whitefly infestations in large or small grows. Two types of wasps are commonly used for whitefly eradication. Eretmocerus emericus tolerates warmer and dryer conditions and is best suited for high-density whitefly populations. Encarsia formosa does well in cooler conditions, higher humidity and low-density whitefly populations. Both of these wasps are excellent for pest management. The mixture of both has successfully been applied for a number of years in large-scale greenhouse operations. As with other treatments, budding is not a good time to be dealing with these critters. It is better to eliminate an infestation before flowering so there are no bug bits in your edibles and smoking products.
“Mites suck the juice out of your plants and poop all over them„
Spider mites are probably the worst of the indoor invaders. One female laying hundreds of eggs over her lifetime can, within a month, be responsible for hundreds of thousands of progeny. To help control populations, reduce room temperature. If these little devils get into your garden and if you do not work diligently to eliminate them they will destroy the plants.
Mites suck the juice out of your plants and poop all over them, producing a protective silk web within which they cocoon themselves as they devour your plants. The damage these very tiny creatures cause is horrific. Blasting them off with a strong stream of water is probably a good place to start when dealing with them. If your plants are in a flowering stage the water blasting method is safe and effective, provided you are thorough.
Many people have success during vegetation using cold-pressed neem oil diluted with water and a little soap. Or a teaspoon of Dr. Bronner’s liquid Citrus- or Peppermint Soap mixed with a teaspoon of oil (such as grapeseed or olive-) in a quart squirt bottle – kept in the fridge – has also been used to great effect. Make sure you shake the bottle before spraying the leaves, to mix the soap and oil together. There are also a few garlic, pepper and cinnamon recipes available online that people swear by.
Pyrethrum spray made from chrysanthemum flowers is another natural remedy to help keep down the numbers. With any sprays or dilutions try a test leaf first to make sure it does not damage them. Too strong of a mix will burn your plants or, even worse, destroy your entire crop. There are several predator mites also available. Predators are a great preventative and an effective control in sufficient numbers. With proper precaution, hopefully you will never need to use them.
Several simple steps can be taken to prevent infestation in your garden. Prevention is the first consideration of IPM. For instance, do not wear outside clothes, shoes or bring outside tools and materials into an indoor garden. Quarantine all of your new plant acquisitions – two weeks is often enough time to determine whether your new plants have stowaways, provided you are inspecting both sides of the leaves. If you lack the space for this endeavor, it is of vital importance to monitor closely and constantly for any signs of infestation.
Observation is the second principle of IPM. Some growers prefer to quarantine and dip or spray plants with chemical insecticides and miticides. This decision poses some serious ethical and moral concerns and brings us to… intervention, the third step on the escalator that is the IPM system.
Nearly all of these chemicals, even natural ones, have the potential to disrupt ecosystems. Insecticides are often toxic to humans and build up in the food chain and water supply. Smoking or eating these residues can pose serious health risks. Many Cannabis patients have severely compromised immune systems and any extra toxins can be detrimental to their health.
Insecticides are classed in several ways, as they are elements and compounds. Resembling salts and silica, they do not contain carbon. Inorganics are very stable and usually water-soluble. Sulfur, the most commonly used inorganic insecticide, was once extracted nearly pure from salt domes. Now, sulfur is produced as the by-product of natural gas and petroleum refining.
Organic insecticides are carbon-based. Made from hydrocarbons, these compounds are also produced from petroleum refining. Natural insecticides or botanics are extracted from plants. Plant chemicals are manufactured by nature for the specific purpose of defending against insects. ‘Natural’ does not mean they are good to smoke or eat either, so be aware when using any chemicals on your crops.
All insecticides tend to fall into two categories. ‘Systemic’ insecticides operate by the plant absorbing the toxin into itself and then the bugs ingest it by eating the plant. ‘Contact’ insecticides operate by using small grains or droplets of chemicals placed on the plant and into direct contact with these critters. Systemic insecticide residue has been found by the US Department of Agriculture in 74% of the lettuce crops tested.
In 2009, the State of California tested eucalyptus pollen and found levels at three times the amount needed to kill a honeybee. This class of pesticide can remain in soils for over 500 days. So plants will produce deadly pollen, nectar and guttation droplets (leaf juice) for several seasons. Seeds germinated after being coated in these pesticides will produce plants with this leaf juice, killing bees within minutes after exposure.
Contact insecticides are not without problems either. Many of these pesticides are considered persistent, which means they do not break down easily in the environment. Some of them take decades to break down, if at all. This causes serious risk to humans, as even low levels of these toxins bio-accumulate in body tissue. Exposure can create immediate problems, or manifest down the road with cancer, organ damage, respiratory- and reproductive problems and nervous system disorders.
These chemicals act as mutagens, causing horrific abnormalities in children of farmers and fieldworkers around the world. Domesticated animals are affected, as well as millions of birds, bats, amphibians and fish that die every year from these pesticides. Application of these chemicals in powder and liquid aerosols guarantees a certain amount will be carried off by the wind and washed into our waterways by erosion. Government testing shows 80% of fresh water fish in the United States are now contaminated.
Cannabis will soon be added to the monoculture crops that promote pesticide use. Supporting bio-sustainable farming practices using natural methods is the only way we can protect future generations from this incredible toxic soup we are creating in our environment.
“Biological pest control is a natural method using the enemies of insect pests and may eliminate the need for insecticides„
Biological pest control is a natural method using the enemies of insect pests. If caught early enough these enemies can eliminate the need for insecticides. ‘Controls’ are not always a quick fix, like chemicals. In a major infestation it is better to reduce the numbers of bugs infesting your garden, and then add these natural enemies. If you do it the other way around you will kill off the helpful insects. Predators are the first of several types of biological control agents. Predators like ladybugs, lacewings, pirate bugs and many nematodes (worms) are hunters that kill and eat their prey. In larval stage some of these predators may eat more insects than they do while they are adults.
Parasitoids are the second type of biological control. Hunters, like the tiny assassinator wasp, do not kill their prey immediately; their victims are hosts for offspring growing inside of their bodies and ultimately causing death. Some nematodes in this category can spring out of soil to catch low-flying insects.
Pathogens are the last type of biological control. These microbial insecticides, bacteria, viruses, fungi – or the toxins they create – are important agents that limit insect populations. There are many benefits to using these controls. Targets for these agents are narrow, unlike broad-spectrum pesticides, which kill helpful insects indiscriminately. These methods are also very unlikely to damage water quality, the environment – or your crops. The disadvantages are that it can take more time, planning, management and education. The best time to use biological controls (as with any other kind of intervention) is during vegetation, because if you are flowering with an infestation you are already too late.
Prevention, observation and intervention are the three stages of integrated pest management. If you are diligent this process can reduce or eliminate the need for pesticides. Take the right steps to stop infestations before they occur. Monitor incessantly to be aware of intruders. Deal with them in a commonsense way to eliminate damage to the environment and to protect the people you love.