I planted sunflowers last year and I never trimmed or cut the stalks when they died. I don't know if they are annuals or perennials. Is there a way for me to tell which they are? Also, will they not grow back this summer if I did not trim them in early winter?

maybess96
Sunflowers are annuals. You can remove the stalks. However, many sunflowers reseed freely if you didn't cut off the flower heads or the birds didn't eat them all. Watch for seedlings soon.

In my area, some of the native bees will nest and over-winter in the old dry stalks. I leave them standing. No need for buying a native bee house!
They are annuals, but do re-seed readily. I also add some fresh seeds in the Spring. The new sprouts will come up between the old stalks. I find this helps keep the dogs--and me--from accidentally trampling them.
There are some perennial sunflowers, they're a bit different, I don't know if they grow in your area. Maximillium sunflowers do well here, but they are big rangy plants that can spread, and tend to keep out any other annuals or perennials. The birds like them, but they don't have the sunflower seeds we're more familiar with.

I just want to add that there are perennial sunflowers. The flowers are smaller, as are the seeds, but, you know, perennials vs annuals..... The perennial types can be cut before full growth to limit the height. At this place, perennial sunflowers really draw American Goldfinch (Spinus tristis).