Whitefly are tiny white insects commonly found on the undersides of leaves, especially in greenhouses, conservatories, and sheltered patios. They weaken plants by sucking sap and can be persistent if not dealt with early.
How to Spot Whitefly
- Small white flies flutter up when you touch the plant
- Sticky residue (honeydew) on leaves or nearby surfaces
- Yellowing or weak growth
- Black sooty mould growing on the sticky residue
Why They Appear
Whitefly thrive when plants are:
- Warm and sheltered
- Crowded with poor air circulation
- Stressed or under-watered
What Helps
- Check the undersides of leaves regularly
- Remove heavily affected leaves
- Gently hose plants to reduce numbers
- Keep plants well watered and spaced
Biological Control
A natural, chemical-free option:
- Use Encarsia formosa, a tiny parasitic wasp
- It lays eggs inside whitefly larvae, stopping them developing
- Best used early and regularly
- Works well in greenhouses and indoor growing spaces
Biological controls are safe for people, pets, and beneficial insects.
Top Tip
Whitefly are easier to manage little and often. Regular checks, healthy plants, and early biological control keep them under control without harsh chemicals.
