How to Get Rid of Ants and Other Insects in Your Grow Room

How to Get Rid of Ants and Other Insects in Your Grow Room

All growing things are subject to pests and diseases. It’s part of some larger plan, they say. You know, there’s a natural cycle to all living things. If they were not subject to some threats, they would not strengthen and evolve.

But, it’s also true that humans are inclined to fix things. The thinking goes that, if it’s broke, you’d better fix it. And, when those life forms directly impact our economy, health, or pleasure, we feel called to right things.

Your cannabis grow room may not strike you as having such noble ends, if you want your product to thrive and payoff in many ways, you need to know how to get rid of ants and other insects in your grow room.

How to spot them and what to do

1. Ants love cannabis, too.  Attracted by the cannabis oils, resins, and boric acid, they will find their way to your plants. But, they may be a sign that you have aphids and whiteflies.

There are any number of remedies for ants, but you should look for those that won’t damage your plant and product.

  • Cinnamon mixed with the potting medium will drive ants away.
  • Borax or dried mint applied at the source or their mounds will kill the ants and their colonies.
  • Alternatives like apple cider vinegar lure the ants away from your plants.

2. Fungus Gnatslarvae thrive in dark damp conditions where they attack seedlings and roots to weaken plants and enable other marijuana diseases. They feed on natural fungus at the soil level. They work through that to the root systems where they stunt the cannabis plant’s growth. You will see them flitting about, but if you don’t, their damage will appear in discolored and misshaped stems and leaves.

Indoor cannabis growers use:

  • Food-grade Hydrogen Peroxide or 100% rubbing alcohol mixed 1 to 4 in water will hurt if not destroy all your gnats.
  • Sand confuses gnats, so topping off the growing medium will discourage them.
  • Apple Cider Vinegar and a couple drops of liquid soap, in small jars, will lure and kills the gnats.
  • Potato Slices (1”x1”x0.25”) laid on the surface of the growing medium and replaced every few days offer the gnats an alternative breeding ground.
  • Chamomile Tea and Ceylon Cinnamon will control the fungi that the gnats feed on if you add it to your watering can.

3. Spider mites (Tetranychus urticae) and their eggs appear as tiny dots on the downside of the plant leaves on cannabis and many other garden varieties while they suck the life from the plant. The topside of the leaves shows yellow-white sports as they die and drop off. You can check for the reddish-brown mites with a magnifying glass, but their webs will appear if you spray stems and under the leaves with light spray of water. Unfortunately for gardeners working in hot, dry conditions, these pests grow quickly and prolifically.

Technically, spider mites are not true insects. They have more in common with scorpions, spiders, and ticks. And, they can be especially harmful in greenhouse environments where the unless the temperature and circulation are managed.

Common organic treatments for spider mites include:

  • Diatomaceous Earth, according to, “is an amazing, 100% product built from tiny fossilized water vegetation. D.E. is a naturally produced siliceous sedimentary organic mineral compound from minuscule skeletal remains of unicellular algae-like vegetation known as diatoms. These types of plants have been a part of the earth’s ecology since ancient periods.” It is used to rid us of pests, including bed bugs, crickets, fleas, ticks, spiders, and more. You just dilute ½ tsp. into a spray bottle to reach under the leaves where the mites live, breed, and feed, and/or you can add it to your growing medium. An increasing number of people even take D.E. internally to kill parasites.
  • Insecticidal Oils use natural oils from peppermint, rosemary, and NON-GMO soybeans. Sprayed on your plants according to directions, the oils kill on contact. Because these oils naturally contain terpenes and terpenoids, they confuse and repel insects with their neurotransmitter disrupting properties. It’s sort of like fighting fire with fire.
  • Neem Oil is every organic gardener’s fallback friend. But, when applied, it can alter the taste and smell of the product. So, you’ll want to avoid spraying flowering plants. It’s a natural tree product and changes the pests’ behavior instead of killing them on contact. You see it makes the bugs nauseous and infertile. Unable to mature, they stop breeding.

4. White Flies (Trialeurodes vaporariorum) live on chlorophyll and other plant fluids. They will reduce growth and kill untreated cannabis. These little white “moths” will take flight if you gently shake the leaves. When they feed, they secrete honeydew which, then, draws ants.

The greenhouse variety of whitefly has caused crop loss on over 250 plants. They are recognized their white, waxy coating and wings parallel to the leaf surface. Best Seed Bank warns, “Indoor grow rooms where the temperature is usually optimal for these insects means they can multiply their population x 200 every month. Since the females lay an average of between 180 and 200 eggs, which means it can quickly become an overly abundant and damaging pest for our plants.”

Some organic treatments for greenhouse whiteflies are:

  • Chrysanthemum-based, natural pyrethrin insecticides should be applied every 10 days.
  • Yellow-colored adhesive mosquito traps attract whiteflies.
  • Potassium, neem oil, and water mixture form a soapy solution you apply to the top- and underside of each leaf.
  • Natural enemies are parasitoids that attack whiteflies. These include Encarsia formosa, Eretmocerus eremicus, and Delphastus catalinae. Each operates differently and may take 1 to 2 weeks to take effect.

Basic steps from the start

Quality growing media go a long way to forestalling the infestation of insects that damage cannabis. Indoor growers especially must manage heat and humidity. And, they must provide the circulation strong enough to discourage bugs settling on and attaching to plants.

Organic stalwarts like diatomaceous earth, neem oil, and beneficial nematodes work on all pests if you study their use and applications. But, regardless of your choice, you must make this a running discipline:

  • Kill as many pests as you can with integrated organic treatments.
  • Repeat a few days later and more until you think you have them under control.
  • Then, repeat yet again.

Insects will not up and go away without treatment, and they will be back without preventive care. So, if you want quality and purity in your cannabis crop, you must learn how to get rid of ants and other insects in your grow room.