Except for Botanical Interests, Johnnies, Territorial and Kitazawa, I don't believe what I read on a seed packet until I double check online.
Even then, there is a lot of variation in advice. I agree with this Idea strongly: check their requirements.
But double-check. Then give the plant what it is said to want if you can, but can't provide that, don't give up on the plant without trying to see if it will indulge you in the micro-climate you CAN give it. And experiment to see if it might like something a little different where YOU live.
Then save seeds for a few years from the happiest plants, and see if they can adapt to you.
Even worse than seed packets are many seed catalogs. Before you place the order, they will tell you that EVERY variety they sell is the "easiest, sweetest, highest yielding and favorite" variety ever. And good luck being told that a seed might be hard to start, like "needs stratification"!
One thing that I take with a grain of salt even from trusty sources is "sun exposure". If the vendor is located in Texas or Nevada and says "part shade", that may not mean it wants "part shade" in a far-North, cloudy climate.
But if a Canadian vendor says "cold-tolerant short season crop", I believe them!
And if a deep-South vendor says "heat-tolerant", I believe that.
