Ornamental Crop IPM Module
Practical IPM plan for ornamental crops covering bedding plants, pot plants, propagation, glasshouse ornamentals and mixed protected ornamentals.
This page focuses on thrips, aphids, whitefly, spider mite, mealybug, sciarid fly, Botrytis and propagation hygiene.
Quick summary
Main pest risks
Thrips, aphids, whitefly, spider mite, mealybug and sciarid fly.
Main disease pressure
Botrytis, mildew and propagation diseases increase in dense humid crops.
Main IPM principle
Find hotspots early and prevent pests moving between crop batches.
Ornamental crops are among the most biologically diverse production systems.
Risk varies depending on: - crop species - propagation source - crop density - temperature - humidity - crop turnover speed - flowering stage - cosmetic quality standards
Many ornamentals have extremely low tolerance for visible pest damage.
Main pest risks
| Pest | Risk level | Key trigger | Inspect |
|---|---|---|---|
| Thrips | Very High | Flowers and warm protected crops | Flowers and growing points |
| Aphids | High | Soft growth | Shoot tips and young leaves |
| Whitefly | High | Crop carryover | Lower leaves |
| Spider mites | High | Hot dry crops | Lower leaves and hotspots |
| Mealybug | Moderate–High | Dense sheltered crops | Leaf axils and stems |
| Sciarid fly | Moderate | Wet propagation media | Compost surface |
| Leafminer | Moderate | Protected crops | Leaf mines |
| Botrytis | High | Dense humid canopy | Flowers and old tissue |
Crop stage plan
| Crop stage | Main risk | Practical focus |
|---|---|---|
| Propagation | Sciarid fly, damping-off, aphids | Clean trays and hygiene |
| Young plants | Aphids, whitefly and thrips | Early biological foundation |
| Rapid vegetative growth | Aphids and Botrytis | Crop balance and airflow |
| Flowering crops | Thrips and Botrytis | Flower inspections |
| Warm weather | Spider mite and thrips | Increased scouting |
| Dense mature crops | Mealybug and hidden hotspots | Deep inspections |
| Crop turnover | Carryover pests | Clean-down and sanitation |
Monitoring plan
| Area | What to look for | Frequency |
|---|---|---|
| Flowers | Thrips and Botrytis | Weekly |
| Growing points | Aphids and distortion | Weekly |
| Lower leaves | Whitefly and spider mite | Weekly |
| Leaf axils and stems | Mealybug | Weekly |
| Sticky traps | Flying pests and pressure changes | Weekly |
| Propagation media | Sciarid fly and algae | Weekly |
| Dense canopy areas | Hidden hotspots and humidity | Weekly |
Environmental risk
| Condition | Likely issue | Management response |
|---|---|---|
| Warm flowering crops | Thrips | Increase flower inspections |
| Hot dry conditions | Spider mite | Reduce stress and inspect hotspots |
| Soft lush growth | Aphids | Review crop balance |
| Dense sheltered canopy | Mealybug and Botrytis | Improve airflow |
| Wet propagation media | Sciarid fly | Improve dry-down |
| Crop overlap | Whitefly carryover | Separate crop batches |
| Poor hygiene | Pest bridges | Clean benches and pathways |
Biological control programme
Preventative phase
Focus on:
- early predator establishment
- clean propagation
- sticky trap monitoring
- crop separation where practical
- reducing carryover between batches
- avoiding unnecessary disruption
Active crop phase
During production:
- inspect hotspots weekly
- monitor flowers separately
- maintain beneficial continuity
- avoid allowing isolated hotspots to spread
- remove heavily infested plants where practical
Flowering crops
Flowering ornamentals create ideal thrips conditions.
Focus on:
- flower tapping
- predator continuity
- hotspot management
- airflow
- avoiding hidden flower debris
Pest-specific notes
Thrips
Thrips are one of the most important ornamental pests.
Key actions:
- inspect flowers regularly
- monitor growing points
- maintain predator continuity
- avoid allowing hotspots inside flowering crops
- reduce hidden flower debris
Aphids
Aphids build rapidly on soft ornamental growth.
Key actions:
- inspect shoot tips
- avoid excessive soft growth
- preserve parasitoids and predators
- respond early to colonies
Whitefly
Whitefly often persists between ornamental batches.
Key actions:
- inspect lower leaves
- avoid crop bridges
- monitor sticky traps
- maintain biological continuity
Spider mites
Spider mites increase during hot dry periods.
Key actions:
- inspect lower leaves
- monitor warm dry bays
- reduce plant stress
- reinforce hotspots early
Mealybug
Mealybug often hides deep inside dense crops.
Key actions:
- inspect stems and leaf axils
- isolate hotspots
- inspect incoming plants carefully
- avoid allowing populations to establish unnoticed
Sciarid fly
Sciarid fly is strongly linked to wet propagation systems.
Key actions:
- avoid overwatering
- manage algae
- inspect propagation benches
- maintain dry-down where possible
Leafminer
Leafminer reduces crop quality through visible mines.
Key actions:
- inspect leaves regularly
- remove heavily mined tissue
- monitor adult activity
- preserve parasitoids
Disease and hygiene notes
Ornamental crops are vulnerable to:
- Botrytis
- mildew
- damping-off
- humidity-related disease
Useful actions:
- improve airflow
- reduce overcrowding
- avoid prolonged wet foliage
- remove old tissue
- maintain clean benches and propagation systems
- avoid crop waste build-up
Canopy and hygiene
Good ornamental crop management improves:
- airflow
- visibility
- crop uniformity
- biological control stability
- disease prevention
Useful practices:
- separate crop batches
- remove old plant material
- clean benches and pathways
- reduce overcrowding
- maintain airflow between crops
- avoid hidden humid pockets
Seasonal calendar
| Period | Main IPM focus |
|---|---|
| Propagation | Hygiene and sciarid fly prevention |
| Young plants | Aphids, whitefly and early thrips |
| Rapid growth | Crop balance and airflow |
| Flowering crops | Thrips and Botrytis |
| Warm weather | Spider mite hotspots |
| Dense mature crops | Mealybug and hidden infestations |
| Crop turnover | Clean-down and sanitation |
Linked tools
Use this module alongside:
Key message
Ornamental IPM depends heavily on prevention, hygiene and early hotspot detection.
The strongest programmes maintain beneficial continuity, reduce crop stress and prevent pests moving silently between crop batches and propagation areas.