I am collecting a rather large community of aphids on my parsley plants, despite random spraying with an organic bug killer (Growing Success Veg and Plant Bug Killer). I held the pots upside down and gave the plants a good soaking with it in the evening at least three times over the past couple of weeks. Even if it's organic, I still don't like the idea of spraying too much mystery liquids all over something I will soon consume (if the aphids don't get to it first). Anyone have any suggestions of what works for them?

Where are you keeping your parsley plants? I've never had any problems with aphids on parsley grown outdoors, either in pots or in open ground.

my parsley is outside in a plastic greenhouse with ventilation...and seems fine...growing well and no bugs at all, the pots were on the windowsill prior to that! is there anything else that you are growing around the parsley, another plant, that might attract the aphids?

Squish them with your fingers. It's not pleasant, but I prefer it to spraying, which costs money

You could also try and attract predators (ladybirds, hoverflies) with something like Limnanthes.

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For Aphids, why not make up a spray that you know the ingredients are safe.
Try this, into 500 ml of water add 1 tsp eucalyptus oil, 1/2 tsp dishwashing liquid
give a good stir and then spray your plant.

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Give the plants a feed too- the aphids will be draining it of nutrients.

Aphids seem to overwinter on our parsley, too.

Then they pass on to the strawberries!

To deal with them organically you need to take your time and go over the plants carefully, either squishing or spraying. The soap/ oil mixture needs to actually touch the aphids and you will need to do it every week until things improve. If there are ants around - which guard the aphids in order to harvest their sweet excretions - it's much harder to keep things under control. As Nicos says, you need to feed the plants too to help them keep going.

Be persistent - that's the best advice I can give.

I understand what you are trying to say, but you are not actually supposed to consume dishwashing liquid and eucalyptus oil either!! I am sometimes happier with an (organic) spray that has been tested rather than experimenting on myself

Thank you for the suggestions. The parsley is in several pots on my patio in a sheltered shaded position (it's the only area I have outside the flat). It's green, healthy, and growing well.. but some bits are yellowing in the lower area of the plant. No ants around either, so I won't have to deal with that.
Sounds like I'll just have to go on a major attack and squish as many as I can before doing lots of spraying. I'm noticing some on my lettuce now.. so I need prevent them going any further.

do you have some flowers around? I noticed that aphids like better everything that smell sweet!
I had the same problem last year, but as soon as I put my pot close to the sweet peas, they vanished! Either they went away, or they have been eaten by something lurking in the flowers...

If you get your hose to a fine but strong spray a simple jet of water is enough to kill most aphids. I take the rose off the end of my hose and just put my thumb over it so it's strong enough to wash off (and kill) the aphids but not so strong it makes holes in the leaves.

If that doesn't work, try getting some lacewing larvae for your greenhouse. They consume hundred of the blighters every day and will hopefully breed and give you a lacewing army in your garden year after year.

If you google 'lacewing larvae' there are a few people who sell them. I think it's around £15 for 500 but that might mean you never have to worry about aphids again 'cos nature's doing the hard work for you.

Go inside and rinse your parsley under the cold water tap then make sure all the greenfly are gone. Put you parsley in the garden. Its a hardy little plant will taste better and fend for itself if you do that. I never spray herbs.