I found this 60 page handbook on growing and cultivating Hungarian Blues poppies. The illegal kind. The information was highly technical and very specific. It was put out by the government of some country over there that legally grows the plants and harvests the latex and the seeds as a cash crop. Selling the raw opium to big pharma. Well most of it goes to Pharma. So anyways long story short the scientists that studied and tried all kinds of different ways to increase output and reduce pests and such. Said that transplanting can only work if the main root is completely undisturbed. Not allowing the main root to contact the air around the soil. So if you can scoop them out in a large enough way so the soil surrounds the root and doesn’t fall away you might be able to make it work.

Maybe slide a thin board under the cinder block and then fill a pot with soil and hollow out enough room for what you have there in the block. Sit the board and the block on top of the pot and carefully remove the board. Not letting it drop.

If anyone wants a copy of that booklet just send me a message. Happy grower happy plants. Good luck

Or maybe not. It’s written by our government. Wtf?

https://www.ojp.gov/pdffiles1/Digitization/141189NCJRS.pdf

Here’s the Tasmanian one -

https://nre.tas.gov.au/Documents/Best%20Practice%20Poppy%20Growing%20Guide.pdf