Can you give us more information? Pictures would be good. What crops are these and where are they growing geographically speaking? You refer to 'dish soap' but then you value your plants in pounds. So are you in the UK? Also indoors or out? In the ground or in containers? Outdoors whitefly is really not that common except on Brassicas and they don't do a lot of harm. So the next question is are they definitely whitefly?

White Fly sticky traps work pretty good. You just have to watch out so you don't get the 'sticky' on you when gardening.

Sticky traps aren't recommended for garden (outdoor) use but only for the greenhouse or tunnel. Not only are they not effective in controlling these insects in the garden, but attract nontarget critters like butterflies, bees, anole lizards, birds, and predatory insects.

Im in the uk theyre definetely whitefly look like littke white moths looks like snowflakes when you disturb them Nd theyre mainky on my sage but theyre starting to appear on my pepper and tomato plant.

Ive found a chemical spray thats approved for use on tomatos peppers and fruit but doesnt say about using ir on herbs but I will still use it on them as it cant be any different. Dont normally do chemicals but they wont budge naturally.

Also theyre doing damage leaves are turning yellow

This is very odd. I have never know whitefly on anything other than Brassicas outdoors. Are these crops under glass? I'm guessing so if you are growing peppers and tomatoes. Glasshouse whitefly

Sage should be bomb proof in our climate and never need any pesticides of any sort. If the sage is inside take it outdoors and hose it down. Then leave it outside permanently.

Pictures of your set up would still be very useful.

Its all outside the tomatos and peppers will be replacedbnext year as i dont have a greenhouse and the sage oregano and other herbs are outside in a raised wooden flower box thing

Ive sprayed thembdown and sprayed down with washihg up liquid and water they keep coming back theyre definetely whitefly as they all fly offbl like snowflakes whenbdisturbing plant and land back on another leaf

Well I'm completely stumped, then. I've never know whitefly to be a problem outdoors (except on Brassicas, and they have a species all of their own) in all my years of gardening.

Any chance of some pictures of your set up? We might be able to come up with some suggestions.

BTW even if you did have a greenhouse you'd be replacing the tomatoes and peppers every year. And I am a bit surprised that you reckon this lot is worth a few hundred pounds. Did you buy some kind of fancy potted plants? Are you growing large numbers?

With all the bedded plants trees bushes and other stuff ir came to alot most were potted

I just got a spray called bug clear ultra gun is there any reason it can only be usef on listed crops like apples pears cherries and peppers etc but not herbs or fruit bushes? Would it do ajy harm just using it on the rest too. Everything in my garden is riddled now so i dont care whatvit takes my oregano is dying now too.

Always follow the instructions. If you have questions email the company. Don't make it up as you go along.

However, I am having real trouble believing that your garden is in such a state solely from whitefly. I have gardened for over 50 years in the UK and have never known that to happen. Oregano is absolutely foolproof. It's a hardy native species for goodness sake. I am wondering if all the gloop you are spraying around willynilly is actually exacerbating your troubles.

If you could just favour us with some pictures we could help you much better.