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Bio-controls: putting good fungi and microbes to work
Some of the best organic pest control isn’t a spray at all — it’s a living thing. Meet the beneficial fungi and microbes that quietly do the job for you.
The most elegant organic pest control doesn’t come in a spray bottle — it’s alive. Beneficial fungi and microbes turn the tables on pests and diseases by infecting, parasitising or simply out-competing them, and they keep working long after a spray would have washed off.
Two are worth every gardener’s attention. Beauveria bassiana is a fungus that infects soft-bodied insects — mealybugs, whiteflies, thrips, aphids — and kills them from the inside. Trichoderma viride is a soil fungus that suppresses the nasties behind wilt and root rot. Build these into your routine and you’re not fighting pests so much as employing an invisible workforce to do it for you.
Build them into the soil
Mix Trichoderma viride into your compost or potting soil at planting. It colonises the root zone and crowds out wilt-causing fungi before they get a foothold.
Spray Beauveria onto pests
Apply Beauveria bassiana to plants with soft-bodied pests. The fungal spores infect and kill mealybugs, whiteflies, thrips and aphids over a few days.
Don’t undo your own work
Broad-spectrum sprays — even some organic ones used heavily — kill beneficial fungi and predators too. Use targeted sprays sparingly so your bio-allies survive.
Keep conditions on their side
Living controls work best in a living garden: healthy soil, compost, mulch and moisture. Feed the system, not just the plant.
The biological allies worth knowing
- Beauveria bassiana — a fungus that infects and kills soft-bodied pests — mealybugs, whiteflies, thrips, aphids
- Trichoderma viride — a soil fungus that suppresses the fungi causing wilt and root rot; add to soil or compost
- Ladybugs & lacewings — not microbes, but the same idea — living predators you encourage rather than buy
Frequently asked questions
What is Beauveria bassiana used for?
It’s a beneficial fungus that infects and kills soft-bodied pests like mealybugs, whiteflies, thrips and aphids — applied as a spray.
What does Trichoderma viride do?
It’s a soil fungus that suppresses the fungi causing wilt and root rot. Mix it into soil or compost as a preventive.
Are bio-controls safe?
Yes — these fungi and predators target specific pests and are safe for you, your food and the wider garden, unlike broad chemical pesticides.