Giant sunflower

Each year I try to grow giant sunflowers for fun, to see how tall they can get. 

This one's grown much higher than the 2m bamboo cane that supports it. 

It looks like it's now over 4m tall and the main flower is at least as big as a human head!

The only downside is I haven't been able to cut any flowers, not even side ones, but sometimes it's nice to just let a flower do its thing and not intervene.