Sunflowers fading

kw: nature, wildlife, conservation

My sunflower plants are done for the year. In a summer of recording bee activity for The Great Sunflower Project, I learned a few things:

• At this latitude, don't bother planting seeds until late May. The first plant didn't come up until June.
• It takes another month for the first flower to appear.
• On a robust plant (I had one very robust plant and two much smaller ones), a new flower will bloom every 3-4 days.
• Only the latest 2-3 flowers have any pollen.
• Don't expect to see honeybees; they concentrate on nectar-bearing blooms, and sunflowers have no nectar. (The GSP is all about native pollen-gathering bees)
• Goldfinches love half-ripe sunflower seeds. They picked the flower heads almost completely bare within a couple of weeks of each one getting seed development.
• There are five common species of native bee in this area: two sizes of bumble bee, 30mm long and 25mm long; a green-thorax-black+yellow-abdomen mason bee of the genus Osmia, 20mm long; a small green bee, 15mm long; and a bee colored like a honey bee but about 18mm long (honey bees are 25mm long).

During just over 60 days that my plants bloomed, I made more than 40 observations of bees, plus a few days when no bees landed on the flowers. The mason bees were most frequently seen, followed by the smaller bumble bee. I had a variety of other blooming plants that came and went in that time. The chives brought the most bees; they have plenty of nectar, though the flowers are very small. They were the only place I saw honey bees. The most common nectar-gathering bee, however, was a tiny black bee, 9mm long or less.

I am looking forward to next Summer.