Do sunflowers need to be pollinated?

[Joe K]

I'm guessing the answer is 'yes'.

See, in late September, I made a glasshouse/cloche, part wood, part glass, about the size of a large wardrobe, and kept heated, so that a sunflower I'd planted late would survive, hopefully. It did pretty well, and produced a bud, but not a large one. Then it produced several more buds just last week, and I snipped off the first one. Having inspected it a few days later, though, I've concluded that it never grew any larger than 2 inches across (the middle bit) because bees couldn't reach it, as I'd made it too airproof, in order to keep the heat loss down.

Live and learn (mostly, learn to plant sunflowers earlier, but the chickens complicate things).

[Deleted]

Yes, I agree that sunflowers would almost certainly require pollination in order to produce a good crop of seeds; but it could easily be done by hand, using a small brush. That's what some indoor tomato growers do, apparently. Wikipedia says that some sunflowers self-pollinate, but I know that the best pollination is provided by bees, even with self-pollinatiing and some wind-pollinated plants (e.g. oilseed rape).

I believe that the majority of plants will accept their own pollen. Domesticated varieties of apples and pears are notable exceptions to this rule.

It does also occur to me that the plant knew perfectly well what time of year it was from the number of hours of light that it detected, and refused to produce seeds for this reason.

You're welcome to grow some sunflowers on my allotment next year. I grew some, of a number of varieties, a few years ago. The ones grown from black sunflower seeds taken from wild bird food did very well. I left them for the birds to eat over the winter.

I didn't know that you kept chickens. It's become a very popular pastime lately. Black sunflower seeds are said to be good for chickens. They seem quite easy to grow.
birding.about.com/od/birdfeeders/a/blackoilsunflower.htm

[Joe K]

We've had bantam chickens, and for a while two blacktails, for a few years, though after the last rooster died (tangled up in some fencing after a cat spooked it, it seems), we're waiting for them to die off now. The kids seem to be (marginally) more interested in their guinea pigs now.

One of the new buds has opened, so I'll try giving that a gentle brush and cross my fingers...