With the growing concern over pesticide use on cannabis, many growers are taking a more organic approach to pest management. When bugs start to take hold in the grow room some of the best options are ones that nature designed to fight the problem instead of relying on synthetic products. For every insect that eats your plants, there is a predatory insect that hunts down and eats it.  That is how the cleanest and most pesticide-free cannabis is grown.

The concern over pesticide use is growing and many products that were once used regularly are being banned from use as more research is done on cannabis. Pesticides normally used on crops are generally never burned and inhaled so they are safe to use on produce but when they are used on cannabis they quickly become dangerous. Even organic products like neem oil can affect the flavor and quality of buds if sprayed when the plant is flowering. There are several enzyme-based products that are much safer and have a less residual presence on the flower but when sprayed they often increase humidity in the room and this can lead to molds and mildews. When plants are in the vegetative state molds and mildews are easier to prevent. Frequent spraying is the best option to prevent bugs before the plants enter the flowering stage when spraying is undesirable. A good pest management regime is to spray vegetative plants every 2-5 days with an organic pesticide and rotate between a few different ones to keep tolerances from forming. The solution to bug problems in flower can be as easy as keeping grow rooms clean and by introducing beneficial insects.

Growers often have issues with spider mites and suffer losses in yield and quality because of it. Luckily, these mites are some of the easiest to prevent by introducing predator mites before the onset of infestation. Spider mites have a quick reproduction cycle and most predatory mites cannot keep up once spider mite numbers are high. Predatory mites are the easiest to introduce and some of the most effective ones are Phytoseiulus persimilis, Amblyseius andersoni and Amblyseius swirskii. These three species are readily available from online sources. Phytoseiulus persimilis is available in bulk form to spread near the plants.  Amblyseius andersoni and Amblyseius swirskii come in small packets that are hung on the plants and disperse mites at a controlled rate over a period of four to six weeks. These three predators thrive at ideal temperatures for growing cannabis, however, they do have trouble keeping up once spider mites have formed their infamous webbing.

Phytoseiulus persimilis
Amblyseius andersoni
Amblyseius swirskii

Spider mite problems can occur in flower when the grow room is too warm. In those instances, the best option is to diversify your predatory insect army and use a range of mites and other insects. Amblyseius fallacis is a species of predatory mite that is especially happy in warmer and dryer environments so introducing large quantities of these can help decrease numbers. When mites can’t handle the problem larger insects are needed. Feltiella acarisuga is a small predatory gall midge that feeds on spider mites when it is a larva and adults actively seek out spider mites and lay eggs next to the colonies. These small larvae quickly decimate the population of spider mites and once they hit adulthood they can fly and are very mobile allowing them to seek out hidden colonies of insects. Another option is the small ladybug Stethorus punctillum it is the most expensive option but the most effective. They smell out the spider mites and eat around 40 mites per day and females lay 15 eggs every day.

Stethorus punctillum
Feltiella acarisuga

The wonderful thing about predatory bugs is they are not the pickiest of eaters and will often consume a multitude of prey items. A. andersoni and A. swirskii both consume other types of mites and A. swirskii is a voracious predator of the larval stage of both thrips and whiteflies. A. fallacis, S. punctillum, and F. acarisuga are all generalists when it comes to the species of mite they feed on and will quickly switch between prey items if a variety of pests are present.  Introducing these species will not only keep the insects that you are accustomed to at bay they will also consume any new pests that make their way into your garden.

We all know that organically grown cannabis has a unique quality to it and the best buds are ones that are grown in a system that uses as few synthetic chemicals as possible. When choosing an integrated pest management strategy it is general practice to react to a problem instead of preparing for it ahead of time and most chemicals are used after a problem arises. Insects can be your little garden helpers and make life a lot easier for you by eliminating problems before they occur and by keeping the natural system of checks and balances in place. A good regime is one where vegetative plants are sprayed with organic pesticides and flowering plants are protected by an army of beneficial insects.

Author: Andy Weyers, Head Grower at Choice Organics