[Hey Jude]

Why is it that my lovely flowers at the allotment get knobbled by the first frosts, but the whitefly on the PSB are still going strong, in fact, I swear they're getting worse - does the frost not kill these flippin' pests?  . Jude.

[Babstreefern]

In a word, nothing kills them.  Even the weather we had last winter with all that snow and freezing cold temperatures only slowed them marginally

[rubyrose]

Hi i have the same problem with whitefly on PSB clouds of them. I had them in a tunnel to start with to. Not had frost where we are yet.

[Weston grower]

I've sprayed them 3 times with Provado Ultimate and still they come. Plus we've had a couple  of frosts!!

Anybody know where you get napalm from?

WG

[compostqueen]

I don't spray them, I cover them over with Enviromesh

Does the white fly actually do any damage to them?

[Yorkie]

I've sprayed them 3 times with Provado Ultimate and still they come. Plus we've had a couple  of frosts!!

Please be very careful with repeated use of chemicals.  The following information is taken from the garden database held by defra.

There are 4 Provado Ultimate products currently licensed:

1. PU Bug Killer.  Only licensed for use on ornamental plants.

2. PU Bug Killer Concentrate.  Only licensed for aubergine (protected), house plant, ornamental garden plants, pepper (protected), tomato (protected) - 2 applications max per edible plant, and max 15ml product per litre of water.

3. PU Bug Killer Concentrate 2. Licensed for apple, aubergine (protected), blackberry, blackcurrant, blueberry, cherry, courgette (protected), cucumber (protected), gooseberry, house plant, loganberry, ornamental garden plants, pear, pepper (protected), plum, potato, raspberry, red beet, redcurrant, spinach beet, strawberry, tayberry, tomato (protected), whitecurrant.  Some max 2 applications, some 3, some 4.

4. PU Bug Killer Ready to Use.  Licensed for apple, aubergine (protected), cane fruit and bush fruit, cherry, courgette (protected), cucumber (protected), herb (outdoor), herb (protected), house plant, leafy brassica, lettuce (outdoor use only), lettuce (protected), ornamental garden plants, pear, pepper (protected), plum, plum (mirabelle), strawberry (outdoor), strawberry (protected), tomato (protected), tree (nuts).  Max 1 application for lettuce and brassicas.

Therefore only 1 of these 4 is demonstrated to be safe for use on brassicas - and only 1 application per crop is judged to leave safe residues.

I am not organic or anti-chemical, but do you really want to eat crops which have repeatedly been dosed by a chemical beyond the tested safe limits / which has not been proved safe at all?

[Spana]

What about trying the thing where you hold a sticky board over the plants, tap the plants to make the white fly fly so they stick to the sticky board

[MoreWhisky]

As compostqueen has said , do they actually do harm?

I have them on my spring cabbages under my enviromesh so they got through that to.

[compostqueen]

I think they are just unsightly. My brassicas seem fine, even the cavalo nero with its very bubbly, blistered leaves.

I think the whole point of growing your own is to eat veg that is not repeatedly sprayed with chemicals.   

But, each to their own 

[aelf]

I'm told a spray of dilute washing up liquid does the trick but I have yet to try it. If I brush past my PSB, it looks like it's snowing! 

[gimli]

an old chap at my allotments said a week garlic spray would help.

just boil some garlic in a pan of water and pop the liquid into a bottle when cool
dont know if it works yet mind lol

[mumofstig]

please read this befor trying home made pesticides 

http://chat.allotment-garden.org/index.php?topic=65430.msg747547#msg747547