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When you brush past your plants in the greenhouse clouds of tiny white flies fill the air.

Find it on: tomatoes, cucumbers, fuchsias, other greenhouse plants
Time to act: spring, summer, autumn


Turn over a leaf and you'll see 2mm long white flies. With a life cycle of just three weeks, whitefly breed very fast. Both adults and offspring are sap feeders and a severe attack will weaken a plant. They excrete the sticky excess, called honeydew, onto lower leaves where it encourages black sooty mould to grow. If left, this weakens the growth of the plant.


When you brush past your plants in the greenhouse clouds of tiny white flies fill the air.


Hang up yellow sticky traps to catch flying adults. Grow strong-smelling plants, such as French marigolds, alongside your tomatoes as a deterent. Every two to three days spray the underside of leaves with a soap-based spray containing fatty acids to kill emerging adults. When the temperature remains above 10 celsius in the greenhouse you can use a biological control, such as the parasitic wasp, Encarsia formosa, which attacks the juvenile forms of whitefly.

Discuss this problem

Talkback: Whitefly
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poodiecat 24/11/2011 at 15:28

Lice, whitefly and the like can be treated easily with nettles - simply cut fresh ( not dried - has to sting ) nettles and chop, leave in water for 24 hours and apply using a spray bottle ( make sure to use a fine sieve so it won't clog ).
After about five days the water will turn into a fertiliser but won't be scarying the pests away.

poodiecat 24/11/2011 at 15:28

PS: Apologies, forgot to mention the container should not be metal.

small-black-cat 24/11/2011 at 15:28

Useless. I was trying to find out more about a non-chemical treatment for whitefly and link to someone else, but all the webpage did was say 'Done' when I couldn't read it. Really sometimes these things are so difficult.

poodiecat 24/11/2011 at 15:28

How true, more research for alternatives should be done by the publishers.

Spud.T 24/11/2011 at 15:28

I've heard that placing pots of growing mint in the greenhouse will deter whitefly. Is this true?


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