Translated and edited from the book Organic Marijuana, Soma Style: The Pleasures of Cultivating Connoisseur Cannabis by Soma (Quick Trading Company, 2005).
Organic Marijuana, Soma Style is an organic growing book by Soma, a grower who kept his garden indoors in Amsterdam (the Netherlands). It controls pests with neem oil sprayed every two to three days and thousands of released ladybugs. Part 1 corrected two points. First, ladybugs mainly eat aphids and most of them fly away within a day or two. Second, spraying neem into the third week of flower leaves residue on the buds and invites mould.
This part covers what the book leaves out. That means the law on bringing in live insects, and a four-phase programme with no sprays on flowers, rebuilt for a Thai room. It ends with what the book gets right.
This is Part 2. Part 1: 100% Organic Pest Control: Neem Oil Plus Beneficial Insects — and Where the Book's Advice Needs Updating
1. Live insects across borders are a quarantine matter
The book does not mention this at all, and it is important.
Bringing live insects and mites into a country is a plant quarantine matter. Biological control agents are living organisms, and many are not native to the country where they are sold. A non-native predator that escapes can affect far more than your grow room. That is why moving these organisms across borders is regulated.
Translator’s note: In Thailand, importing live organisms falls under the Plant Quarantine Act B.E. 2507 (as amended), and you need an import permit from the Department of Agriculture (กรมวิชาการเกษตร). Microbial products such as Beauveria bassiana, a fungus that kills insects, are a separate case. They must be registered under the Hazardous Substances Act before they can be sold.
Translator’s note: Growing cannabis remains illegal in Vietnam and most other Southeast Asian countries. Nothing in this article applies to growing there.
This section explains the principle. It is not a guide to importing anything.
Translator’s note: If you want to use biological control in Thailand, take these four steps:
- Buy inside Thailand. Thai agricultural institutions and commercial insectaries (farms that breed beneficial insects) already supply other crops. Examples are predatory mites, Trichogramma wasps and Beauveria products. Buying locally means the import question never arises.
- Ask the supplier for proof. For a microbial product, ask for its Department of Agriculture registration. For live agents, ask for evidence that they were bred in Thailand or imported under permit.
- Do not order live insects from abroad yourself. This is a customs and quarantine matter, not a grey area.
- Check the species first. Before you release anything, find out whether the species is native to Thailand or already established here.
Following a foreign book word for word could put you on the wrong side of a law that has nothing to do with cannabis.
What to do: Keep a copy of the registration or the proof of Thai breeding or import for every biological product you buy. File it with your farm records, so you can show where every input came from.
2. A programme with no sprays on flowers, rebuilt for a Thai room
This is the book’s approach rebuilt on current practice. It runs in four phases.
Phase 1: Prevention, the part that actually works
The full checklist is in the topic on integrated pest management (IPM). IPM means combining prevention, regular checks, natural enemies and, only when needed, targeted sprays. The essentials:
- Start from seed or from your own cuttings. This book and True Living Organics, another organic growing book, agree on the main entry route for pests. Cuttings brought in from outside are how powdery mildew, spider mites, aphids and thrips get into a garden. This is the most valuable practice on this page.
- Quarantine anything new for two weeks, away from the main room. In that time, pests or disease that came in with the plant will show before they reach your crop.
- Use the room climate against pests. Spider mites thrive in hot, dry rooms. Keeping humidity around 50–60% during vegetative growth works against them. In flower the priority shifts to botrytis, the grey mould that rots buds from the inside. Good airflow, space inside the canopy and a clean room do that work.
Translator’s note: In Thailand, clones bought from another farm carry real risks. They can bring pests or hop latent viroid (HLVd), and they may not be the strain on the label. If you have no choice, keep bought clones in quarantine for the full two weeks and check them with a loupe before they enter the main room.
Translator’s note: In the Thai wet season, humidity above 60% is normal, so most of your effort goes into bringing it down. A hot, dry room is more likely in the dry season or under strong air-conditioning. That is when mite risk rises.
Phase 2: Sprays during vegetative growth only
- Use neem oil or azadirachtin (the main insect-active compound in neem), insecticidal soap, or a registered Beauveria bassiana product. Spray only when you actually have a pest, not as routine prevention.
- Spray during the dark period or with the lights off, because oil sprays under strong light burn leaves.
- Keep spray dates and predator release dates apart. Wet spray can harm some predatory mites and parasitoid wasps, so release only after the spray has dried and the spray phase is over.
- Stop at the flip, the day you switch the lights to the flowering schedule, or very shortly after it.
Translator’s note: Use only products registered with the Department of Agriculture, exactly as the label says. The topic What You May Legally Spray Under Thai GACP explains why there is no cannabis-specific product list. Registration alone does not make a product permitted on a crop certified under GACP (Good Agricultural and Collection Practice).
Phase 3: Flowering, with predators and climate only
- Release predators that match the pest and are sourced in Thailand. Pest-by-pest choices are in the topic on biological control of spider mites and thrips.
- In hot rooms, choose heat-tolerant species. Above about 30 °C that means Neoseiulus californicus for spider mites and Amblyseius swirskii for thrips and whiteflies. Phytoseiulus persimilis suits cooler rooms only.
- Spray nothing onto flowers. Nothing at all.
- Check the plants every 2–3 days with a loupe (a small hand magnifier). True Living Organics puts it well for spider mites. If you catch the first damage on the upper leaf surface, you still have a chance. If you miss it, the mites spread fast and the plants are soon covered in webbing.
Phase 4: Between crops
In a perpetual-harvest room, plants at different stages share the space so that harvests never stop. Because some plant is always there for pests to live on, this kind of room can never break the pest cycle. If a pest keeps coming back, the strongest fix is to empty the room and clean it.
What to do: Decide now where your plants would go if you had to empty the room. With that plan ready, a pest that keeps coming back means a short break, not a lost crop.
3. What the book gets right
It would be unfair to finish without saying what still holds up:
- The core principle. Medical cannabis needs safer pest control. Today that is a legal requirement, not just an ethical choice.
- Prevention before cure. The whole approach is built on keeping pests out, not on killing them once they have settled in.
- Stopping sprays before harvest. The idea is right, even though the book’s cut-off comes three weeks too late.
- Chemical pesticides kill beneficial insects, so the two methods do not mix. This is correct. It is why you have to commit to a biological programme, not keep it as a fallback. Some “organic” sprays can harm beneficials too, as described under Phase 2.
- Keeping beneficials in the room right up to harvest once the sprays have stopped. This structure is right.
- Ladybugs leave the plants as they dry, and some survive into the next crop. UC IPM, the pest management programme of the University of California (USA), notes that resident lady beetles are important predators, while bought ones fly away within a day or two. Protect the natural enemies that already live in the room.
What to do: Keep the book’s structure: prevention first, early sprays only, and predators through to harvest. Change two things. End all sprays at the flip. Replace ladybugs with predators matched to your pest and your room’s highest temperature.
4. Share what works in Thailand
The theory on these two pages becomes a working programme only once you can actually buy the right agents in Thailand. A regional forum is the right place to collect that knowledge.
If you have used predatory mites or Beauveria in Thailand, reply below with four details: which agent, which pest, the room temperature, and whether the supplier showed a registration or import permit. You can also say what kind of supplier it was, such as a government agency, a university or a commercial insectary. Under forum rules, shop names and contact details belong in the Marketplace section, not in this topic.
Related topics, all linked above: integrated pest management, biological control of spider mites and thrips, botrytis, powdery mildew, and what you may legally spray under Thai GACP.
Translator’s note on the law: This article is technical horticultural information for readers operating legally where they live. In Thailand, cannabis flower is a controlled herb under the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis), B.E. 2568, in force since 26 June 2025. Flower may be dispensed only against a PT 33 prescription, covering at most 30 days. Flower that is sold must come from a GACP-certified site. Flower may not be advertised, and may not be sold online. The Ministerial Regulation on Controlled Herbs (No. 2) B.E. 2569, in force since 30 April 2026, tightened the licence criteria for cannabis flower. The Cannabis Control Act is still a draft: Cabinet approved it on 22 September 2026 and sent it to the House. Importing live biological control agents falls under the Plant Quarantine Act B.E. 2507 and needs a Department of Agriculture permit. Microbial biopesticides must be registered under the Hazardous Substances Act. Growing cannabis remains illegal in Vietnam and most other Southeast Asian countries. Pesticide and biological-control rules change often, so check your national authority’s current lists before you apply or release anything. Nothing here is legal or medical advice.
References
- Soma. Organic Marijuana, Soma Style: The Pleasures of Cultivating Connoisseur Cannabis. Quick Trading Company, 2005.
- True Living Organics (book; cited in the original for imported cuttings as a pest route and for spider mite scouting).
- UC IPM, University of California. Convergent lady beetle, accessed 14/10/2026.