What's the best emergency treatment for severe infestations?
Written by
Liu Xiaohui
Reviewed by
Prof. Charles Hartman, Ph.D.In the case of an aphid outbreak, it is critical to take immediate emergency action to save your plants! You should start with high-pressure water blasting to blast off masses of aphids and follow immediately with soap sprays, all within a few hours. I have saved roses from near complete defoliation using this sequence as soon as I discovered the aphids during peak season.
Immediate Actions (Hour 1)
- Blast plants with 60 PSI water spray
- Apply soap solution to all surfaces
- Isolate affected plants completely
Secondary Measures (Hour 2-4)
- Prune heavily infested sections
- Release ladybugs/lacewings overnight
- Apply neem oil barrier around base
Follow-up (24-48 Hours)
- Reapply soap solution to survivors
- Install yellow sticky traps
- Apply seaweed extract for plant recovery
High-pressure water spraying gives you an instant knockdown. Use the 60 PSI (4.1 bar) setting on your hoses and direct the stream at a 45-degree angle into the undersides of the leaves and the stem junctions. I do this in the morning before 10 a.m. when aphids are moving slowly, and I will repeat it in 30 minutes to catch any pests that may be hidden.
After the water treatment, use soap solution right away. Mix 3 tablespoons (45 mL) of castile soap with 1 quart (0.95 L) of water. Drench every surface (including soil lines). I add 1 tsp of neem oil for the residual protection. I recommend rinsing after 4 hours to prevent the leaves from burning.
Prune strategically, eliminating only those parts that are unrecoverable. Cut at least 6 inches below the infestation with your sterilized pruning shears. I disinfect my tools with alcohol between each cut. Seal the debarked wood in plastic bags immediately to prevent aphids from escaping to other nearby plants.
Release predatory insects overnight to gain extended control. The best way to release ladybugs is to place them in tubes near the affected area during dusk. We also strive to keep the predatory insects in conditions around 70°F (21°C) at the time of release. I provide watering intervals with pebbles or rocks to keep them in the area longer.
Recovery observations last for three days (72 hours). Observe hourly at first with planted plants. I apply seaweed extract to relieve stress. Add supplemental predators if survivors exist. I will continue the isolation period until I have observed signs of new growth with no pest sightings for three consecutive days.
Read the full article: How to Control Aphids: Proven Methods Guide
