This year, the opium poppies I planted didn't come up. I suspect the chickens scratched over the beds where I scattered the seeds, and destroyed any germinating seeds before they had a chance to come up. Luckily, the ones I left to their own devices last year self-seeded.
Poppies growing in wheelbarrow last year:
Self-seeded seedlings coming up in October 2014:
Live poppy straws and seed heads, after flowers petals have dropped, late December 2014:
Dead poppy straws and seed heads January 2015 that remain after my occasional harvest:
Harvested poppy seed heads, pre-seed removal.
Final poppy seed "crop":
All in all, harvesting maybe 50 seed heads, I ended up with a hefty bag of poppy seeds weighing in as shown, at 105 grams. Removing the seeds from the seed heads is a matter of holding the straw ends and simply upending them and shaking them over a container. If I had to harvest them on a larger scale, I'd simply get a supermaket bag, turf the cut heads into it, give it a good shake and then pull out the heads one by one making sure all were empty.
Buying them in the Greggs boxes at the supermarket, you purchase them at $2.29NZ / 40 grams. So, at supermarket rates of 0.57c / 10 grams, my seeds would cost $6 NZ.
I invested no time at all in growing these poppies, and perhaps less than 5 minutes harvesting the seeds. The only problem might be if they spread throughout your garden, but there are worse problems to have. What I should have done differently is tagged the plants with the red petals, and save the seeds from those to sow for next year.