I think that the first 'secret', Windy, is to live in a cool, wet climate. In the wild they grow on the rainy side of the mountains. Their flowers nod downwards to keep the rain out. The west coast of Scotland is probably the best place to grow them in the UK and maybe also Wales. Here in the north we do reasonably OK. In Cambridgeshire I would have thought that you might have a challenge with hot, dry periods.
How would I grow them in Cambridgeshire? Yes, firstly I would create a humus rich soil in the shade. Forget Miracle Grow, it is expensive and I suspect that it is high in nitrogen. The humus material would be, in order of preference, leaf mould, composted bark, soil conditioner, cheap peat-free compost. Our beds have composted bark as humus and I throw some bone meal in as a fertiliser for strong roots and flowers.
The soil needs to be kept moist, certainly in the growing season, and I would suggest misting them if the weather is hot and dry. If you don't have a hosepipe ban then I would water with a sprinkler that throws the water up in the air.
Good luck. If you can grow them they are wonderful plants.

My memory of Cambridgeshire soil is heavy clay. You will need, as Bulba has stated, to create a bed in which you have effectively replaced all the clay to a good foot down to allow the meconoposis to grow. It is going to be a bit of a challenge but they are simply wonderful plants.

One of our Scottish mec. authorities also grows them in large containers in a polytunnel. The plastic tunnel provides good diffuse light and the plants can be easily misted. With a container you can give them exactly what soil you want, Windy, and move the plant to the cool side of the house in hot weather.

Another thing I read about meconopsis - plants you buy tend to have just one crown. If that crown produces a flower, it dies. So you need it to produce another crown to carry on the following year. In the cool, moist conditions BH describes the plants do this, but in warmer, drier conditions they are less likely to do so.

It frustrates me...theres me thinking it must be difficult for me to replicate the conditions of such a beautiful flower... until today i venture up my local GC and what do i find in a 5 for a tenner deal which all the garden centers ive ever visited seem to have you've guessed it meconopsis in compost they most proberbly sell 'And' the week before last me & the other half took a trip to Her majesty's sandringham gardens and yes again i find meconopsis looking lovely growing in soil that looks and feels similar to my own and so you can understand me thinking How are they doing that...maybe i'll never know until i try. BIG THANKS everyone very informative. windy ;)

Wish I could find them at '5 for a tenner'! What have you to lose at that price, Windy? Buy five and try them; treat them as annuals if necessary, they are lovely plants.

Hi Andrew my understanding is that not all meconopsis are monocarpic, but to be sure I asked Ian Christie, a friend of ours, who is a world authority on meconopsis and this is what he said:

"Meconopsis George Sherriff Group (old GS600) we now have at least a dozen named forms which have been around for 20 year at least the GS 600 was collected in 1938ish so we could say it is definitely perennial. Other
perennial Meconopsis are M. grandis Strathspey, M. bailey all forms M. grandis Himal Skies
M. quintuplinervia, M. x cookie Old Rose. We also have a
clay soil here and have made raised beds mixing in leaf mould old compost grit anything we have this works very well."

He also attached a photo which I can't add as a reply but if anyone is interested will put up as a photo stating it is Ian's.

Thanks MG - I know there is a lot of confusion over their perennial-ness so any light on the subject is welcome.

There are always good displays of blue meconopsis at Wisley (20 miles from me) which has very sandy, free-draining soil. But they grow them as annuals and plant new ones each year

The RHS & SRGC have been running a trial at Harlow Carr which, I 'think', is now over all extremely fascinating. There is even a Maconopsis Group but as they meet in Scotland possibly a little far away for you Andrew.

At '5 for £10' Windy, I suspect that you would be getting small plants in three inch pots. These could take a few year to reach flowering size and may well have perished by then. How about paying £5-£10 for one large plant that is already at flowering size and get some enjoyment out of it. If you can manage to keep it going, fantastic, if not you will have had some enjoyment out of it. They are in flower now so I would suggest waiting until next March/April, buying from a specialist nursery, say Blooms at Bressingham, and getting a full seasons value for it.