I wanted to grow peanuts this year, and I've bought seeds, but someone just told me that they don't grow here. If that is true, then I won't plant them, as I have limited space. Can I grow them?
Yes. I grew peanuts two years ago in the Philly suburbs, and have them growing again this year. Biggest problem is that squirrels and rabbits eat the above-ground plants. You need to protect them with some kind of wire fencing. Deer probably would eat them, too, but I'm lucky that deer don't get in my yard.
According to this web site, peanuts can be grown in "Zone 5 or higher":
Peanuts are annual plants related to peas and beans. You can grow them in your garden if you are in USDA zone 5 or higher. They require a long growing season but can be started early indoors in northern regions.
It looks like most of Pennsylvania is in Zones 5b, 6a, and 6b (see map here) so chances are peanuts should grow where you live, although due to the shorter growing season in the northern states, you may do well to start your peanuts indoors early (probably too late for that this year).