How to tell when a sunflower is about to bloom

The Early Russian sunflower's head starting to tilt to the side, showing that it's beginning to bloom

Sunflowers are really cool plants to grow. In the growing stage, they just keep producing leaves and stem, leaves and stem, repeatedly, until they reach the height they want to flower at. You can usually tell from the formation at the crest of the plant whether that cluster is of developing leaves, and when they’re changing to a flower bud (You can see the growing process at this post).

However, when the plant is too tall for you to peek at the top of it, there’s something else that can clue you in…

Firstly, you know how the top of a growing sunflower plant follows the movement of the sun from east to west every day? Yes it does! I haven’t looked early enough in the morning to see how it moves from facing westward to the rising sun, but it does move. Well, when you look at the plant in the evening and it’s tilted towards the east, you know the flower is about to bloom, because sunflowers face east when the flowers open up, and once they bloom, they stop following the sun.

And this was the scenario yesterday evening when I peered upwards at my Early Russian sunflower – it was “looking” in the wrong direction! I didn’t have a ladder handy, but the camera zoom showed me what I needed – a glimpse of folded petals just waiting to start unfurling.

Early Russian sunflower poised to bloom!

Another look today showed the head of the plant continuing its 90 degree tilt, and a better view of the petals starting to reveal the multitude of florets-to-be. Looks like I’ll get to share pictures of a giant sunflower with you after all! 8)

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How to tell when a sunflower is about to bloom — 4 Comments

  1. So are you saying that you can gauge the height they’ll reach by when they start to bloom? This would be useful to know as I’ve just bought some sunflowers in pots yesterday, with no info tag I’m a bit bewildered as to how high they’ll grow (don’t want giants on my small balcony).

    Anyone know how to tell / control the height they grow… please tell me asap?


    • If sunflowers are grown in pots, their size is constrained, so unless they’re in big pots, you shouldn’t have giant sunflower plants. That said, even those grown in the ground can surprise us. I’ve tried growing giant breeds, but have only struck gold once; the plants tend to be smaller than promised. :(

      • This is the first year we have tried growing them and 2 of the plants are well over 8′ tall.