Not very much; growing poppies for personal use is risky, tedious, and often not very rewarding in the end. That's why you see fields of poppies, rather than patches, or indoor set-ups. Not saying, however, that it's impossible to get a little stash of opium from a backyard poppy patch.
Its obvious you never grew poppies before. Man the internet is full of discouraging people....
Each "bulb" contains anywhere from 20mg - 80mg of opium, and each plant has anywhere from 3 - 7 "bulbs".
Lets say you make a garden and grow 50 plants (which is very easy, and they will grow in any climate). Each plant grows 4 bulbs, thats 200 bulbs, and each bulb contains 50mg of opium, thats 10,000mg of opium.
So after spending a good 4 hours in your garden, you manage to scrape out all the opium from your 200 bulbs, and youre left with a container with 10,000mg of opium. Morphine makes up 10% of opium, and a small amount of codeine and thebaine are present also.
Here comes the fun part....
Lets say your opiate tolerance is 40mg Oxycodone, or 1 baggie of H. All you will need for a good high is 20mg of Morphine (assuming you will be smoking your opium). Do the math, 20mg of morphine = 200mg of opium. Time to divide up your 10,000mg of opium into single "hits". 200mg divided by 10,000mg = 50 HITS. Isn't that great? 50 free highs! What I like to do is buy some menthol tobacco from a smoke shop and some rolling papers. Ill roll the tobacco with a single hit of opium (200mg), smoke it up and it's nodsville from there, and its not like a quick oxy high, its a numbing sedating high that lasts HOURS, even if youre opioid tolerant.
Every summer i harvest roughly 1000 bulbs, which really comes in handy because my roxi script always seems to run out early every month. Theres nothing better in the world than smoking a tobacco/opium joint then snorting a couple of roxis.... ahhh heaven. Have fun people.