Sunflowers are annuals but will reseed readily. If you want really big sunflowers you need to buy the type of seed that produces the giants, feed and water them well, and keep the birds and squirrels off of them. I once, long ago, grew two acres of them to feed our livestock. Dratted squirrels got a good bit of them but there was enough for all. There must be a hundred different types of sunflowers out there. If you ever go through Kansas in the summer you'll see acres and acres of them growing. George Janni wrote: > > For years I have wanted to grow those HUGE sunflowers everyone else in the > world but me has. We put black oil sunflower seeds in one of our bird > feeders. This year we have SUNFLOWERS!!! First time. My questions: Are they > perennial? Do they get a bigger diameter as they grow? And how come the > seeds from the packs you buy at the store have a different stem and don't > look as healthy? Thanks!!! > > Janni