When to weed covered bed

[womble]

My brassicas are covered completely by a enviromesh cage this year, I can deal with the cabbage whites, but the whitefly just take over and I've had enough.
I planted out the brassicas while they were really small, to make sure there was no pests hanging on, where they could breed under the mesh, (had that before) and it seems to have worked perfectly.

Now I need to get in and weed, when is the best time to do it to minimise the chances of pests getting in? I presume evening time, but I thought I'd ask opinions.

[Two_Sheds]

Have you got French marigolds in with them? Works for some (not me)

I don't know if there is a favourable time of day for weeding as per whitefly: but do keep on top of it, because some weeds host the whitefly

I've not come across this idea before, but it might be worth a try: spray them with flour & water

[womble]

French marigolds help greenhouse whitefly, not outside whitefly, different species.

The weeds hosting the whitefly doesn't matter, as there are not whitefly in there! Atm, that's why I want to keep them out. Maybe I should fit an airlock

[Two_Sheds]

French marigolds help greenhouse whitefly, not outside whitefly, different species.

I've tried all of them: African, French, Mexican, English. None of them works for me, indoors or out

You may think there aren't any whitefly in there already, but what about eggs? Greenfly appear from nowhere, in a closed room in my house, so I suspect whitefly to have the same mystical ability

[Alison]

Thankfully I've not had that problem as they main issue round here seems to be the flutterbys which thankfully you can see. Usually end up with one getting in at some point but I can manage some squishing. Sorry not to be able to help. By the way, I find the best time to do my weeding is when I have time, it might be morning when evening would be better etc but I never have enough time so if I find a window then I go for it

[Snadger]

There's only one thing for it.

Don a miners lamp, wait until about 2 am when the whitefly are asleep and just for good measure try and make it in the middle of a thunderstorm (as whitefly don't like getting there feet wet)
You've missed the optimum date though, which was April 1st!

Anyway,get stuck into the weeding and hopefully you'll be finished by sun up!