Natural Botanical Pesticide & Fungicide Alternatives Guide (2020)

Whether you’re growing cannabis or vegetables, pests and fungi can be a real problem. There are natural botanical pesticide and fungicide alternatives many growers and gardeners swear by, and we present them here.

This is a guide to some of the best in the market according to real user feedback and our own experiments. We have tested each of these products ourselves. We only sell the ones that pass our tests in the real world.

This is why Grow Supply Shop was founded in the first place, to make sure you’re using products that actually work and work well!

Grow Supply Shop’s Lowest Price Promise guarantees that we will beat the prices of all competitors as well. If you find a lower price anywhere else, let us know.

Furthermore, if you have any questions about your grow, call or text us with your questions for expert growing advice at (800) 587 6207. You can also email us at

Common Pests, Insects & Fungi

The most common cannabis pests and fungi are also common for other crops:

  •         Thrips
  •         Whiteflies
  •         Aphids
  •         Spider mites
  •         Ants
  •         Caterpillars
  •         Snails
  •         Slugs
  •         Leaf miners
  •         Cochineals
  •         Nematodes
  •         Crickets
  •         Grasshoppers

Common cannabis fungi & diseases include:

  •         Marijuana mushrooms
  •         Root rot
  •         Botrytis
  •         Oidio
  •         Fusarium
  •         Mildew
  •         Bold (tizne)
  •         verticilosis


To learn about natural botanical solutions to control these pests and diseases, read on.

Ed Rosenthal’s Zero Tolerance Herbal Pesticide

Controls: Spider Mites, other mites, thrips, fungus gnats, mealybugs, aphids, powdery mildew, caterpillars, whiteflies, scale, ants

Active Ingredients: Essential oils of cinnamon, clove, rosemary, thyme

Used for: Indoor, outdoor & hydroponic gardens

Ed Rosenthall is a horticulturist who developed a reputation as the “Guru of Ganja” and wrote a column in High Times in the 80’s and 90’s. His Marijuana Grower’s Handbook is the all-time top selling book on the topic. He has been a strong advocate for marijuana legalization and for natural botanical herbicides and pesticides.

Ed’s Zero Tolerance Herbal Pesticide is one of the better all-rounders on the market. It’s OMRI certified for organic gardening and made with natural food-grade essential oils. Zero Tolerance evaporates fully, leaving no residue. Customers love the smell of this formula, too.

Zero Tolerance destroys exoskeletons, deteriorates nervous systems, kills eggs, and more.

Warning: The product contains oils that can burn plants if you don’t dilute it.


NPK Industries Mighty for Controlling Mites & Other Insects

Controls (Including Eggs): Adelgids, ants (except fire ants, harvester ants, carpenter ants & pharaoh ants), exposed aphids, apple red bugs, beetles, cabbage loopers, caterpillars, centipedes, earwigs, fruit tree leafrollers, fungus gnats, grape phylloxera, psyllids, plant bugs, scale, sawfly larvae, silverfish, sowbugs, spider mites, spittle bugs, springtails, stinkbugs, thrips, whitefly adelgids, whiteflies, weevils, worms (cankerworms, cabbage worms, webworms), moths

Active Ingredients: Pyrethrins, canola oil

Used for: Indoor, outdoor & greenhouse gardens

Mighty is typically marketed for controlling mites like spider mites during all stages of development, including eggs. It is ESPECIALLY good at killing spider mites. However, the active botanical ingredients, pyrethrin and canola oil, kill a lot more than mites.

Pyrethrin, which kills on contact by paralyzing the pest, is often recommended for cricket and grasshopper control, too. They’re not on the product’s insect list, but it does kill them. For additional effectiveness, use a garlic spray to repel them or sprinkle flour on the plants to prevent them from eating.

Pyrethrin is an extract of the chrysanthemum flower, so it’s suitable for organic growing operations. It’s also biodegradable and has a low toxicity to humans and other mammals.

Canola oil kills a lot of the same insects plus powdery mildew and some aphid viruses. It also helps the pyrethrin stick to the plants and pests.


Ed Rosenthal’s Zero Tolerance Herbal Fungicide

Controls: Everything Ed’s pesticide does plus molds, mildews & fungi

Active Ingredients: cinnamon, clove, rosemary, thyme, potassium bicarbonate

Used for: Indoor, outdoor & hydroponic gardens

Just like Ed’s herbal pesticide, the fungicide is made with the same plant essential oils. This formula adds potassium bicarbonate to the mix.

Potassium bicarbonate changes the surfaces of the leaves in a way that prevents spore growth.


Sierra Natural Science (SNS) Pro Fungicide Concentrate 244

Controls: Fungi & spores

Active Ingredients: Thyme oil, polyglyceryl oleate, cod liver oil, lauric acid

Used for: Indoor & outdoor gardens

This ready-to-use natural fungicide is made of 100% pure thyme botanical extracts. They are food-grade and GRAS (generally recognized as safe). The fungicide is even exempt from U.S. Environmental Protection Agency registration due to minimum risk.

SNS 244 is a topical spray that kills fungi by:

  •         Suppressing the life cycle of spores
  •         Nurturing the plant cells to increase immunity.

Some of the components are absorbed systemically by the plants.

Normally, you only have to spray this stuff once. For larger problems, you can do it every few weeks.

The fungicide is fully biodegradable and non-toxic to humans and animals.




Talk to an Expert for Free
If you have any questions about your grow, or about natural botanical pesticide and fungicide alternatives, call or text us at (800) 587 6207. You can also email us at

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