Overview
This lecture covers effective organic methods for controlling and preventing garden pests, with a focus on safe sprays, preventive techniques, and practical pest management tips.
Effective Organic Sprays
- Bt (Bacillus thuringiensis) targets caterpillars and pest larvae, is safe for humans and beneficial insects, and must be ingested by pests.
- Safer Soap works on contact against soft-bodied insects like aphids and whiteflies; must be sprayed directly onto pests and under leaves.
- Cold Pressed Neem Oil disrupts pest hormones and feeding, serves as both insecticide and fungicide, and provides residual effects.
- Spinosad controls a broader spectrum, including Colorado potato beetles and leaf miners, but may harm beneficial insects; spray at night.
- Pyrethrin is a strong, broad-spectrum knockdown spray; use only as a last resort and avoid spraying beneficial insects.
Preventative and Physical Methods
- Surround Kaolin Clay coats plants, masking them and deterring pests from feeding or laying eggs.
- Diatomaceous Earth physically damages crawling insects' shells, causing dehydration and death; reapply after rain.
- Hand Removal & Vacuuming physically removes pests and egg clusters, especially useful for tough pests like squash bugs.
- Crop Rotation and Garden Cleanliness remove old or infested plants and fallen fruit to break pest life cycles and reduce habitats.
Enhancing Natural Pest Control
- Encourage Beneficial Insects such as ladybugs, lacewings, praying mantis, and parasitic wasps to control pest populations.
- Trap Crops like amaranth attract pests (e.g., cucumber beetles) away from main crops, allowing targeted treatment.
Best Practices and Tips
- Always target sprays directly on pests and under leaves for effectiveness.
- Apply sprays like neem oil and spinosad at night to protect pollinators.
- Use strong sprays like pyrethrin only when absolutely necessary.
- Allow a grace period with no susceptible crops in the garden to reduce pest carryover.
- Regularly inspect plants for eggs and pests to catch problems early.
Key Terms & Definitions
- Bt (Bacillus thuringiensis) — organic bacteria-based insecticide effective on caterpillars and larvae.
- Safer Soap — organic soap spray for killing soft-bodied insects on contact.
- Neem Oil — natural oil disrupting pest growth and serving as a mild fungicide.
- Spinosad — organic, broad-spectrum insecticide from soil bacteria.
- Pyrethrin — potent organic insecticide from chrysanthemum flowers, fast-acting but non-selective.
- Kaolin Clay — mineral powder forming a protective barrier on plants.
- Diatomaceous Earth — sharp, fossilized algae powder that physically injures crawling insects.
- Trap Crop — a plant grown to lure pests away from main crops.
Action Items / Next Steps
- Inspect garden for pests and apply appropriate organic sprays as needed.
- Use physical barriers and preventative sprays early in the season.
- Remove infested plants and fallen fruit to disrupt pest cycles.
- Encourage and protect beneficial insects in the garden.
- Consider using trap crops for targeted pest management.