Sunflower Question

My granddaughter is working on a school project & for an extra bonus point, they gave them the assginment to find out 'Why do sunflowers always face the East?"

does anyone know the answer to this?

TIA,
Jan

Sun rises from east? =)

Hmmm...I believe that is a trick question. Sunflowers are well-known for their heliotropic habits. The may face east in the morning but often tend to follow the sun thru the day.
(What gets me is: if they really are heliotropic, and face west by the end of the day, what makes them turn around at nite so they can greet the sun in the morning? Maybe they peek?)

Hmmm mine never change direction always facing East even when the sun is on their backs?

wolflover, what zone/area/state/country are you in? I'd like to check this out further. Was wondering what altitude/latitude you are in. This could be a cool project to get into.

I live in zone 5 by Albany NY-not sure about the latitude and such? Now thinking I have them in three different areas and they are all facing East. Hope this helps.

Hostan - encourage your granddaughter to go to www.google.com and enter "sunflower east" in the search box. I did this, and found the answer. It relates to the flower being phototropic. Make sure she checks it out.

-Jennifer

I checked my sunflowers this morning (c. 8 am) and they were definitely facing south west and still are. Zone? Roughly equivalent to 7a; in a Swiss Alping valley at 500 m altitude. Could be because behind them (east-ish) are mountains so not much light there early in the morning. I'm just happy they are facing the house and I can see them. Housotropic rather than heliotropic :-) And the house is a field away.

HAH!...I do b'lieve I've got it, by jove!

Yes, they are definitely heliotropic (and Housotropic!).
The following paragraph came from the hyperlink that follows.
"During the bud stage, sunflowers will turn to follow the sun. As the petals open, sunflowers face east to protect their seeds from the hot rays of the sun."
From this site http://www.ext.colostate.edu/pubs/columngw/gr010627.html

Not too sure about the "bud stage" and how long it lasts. I know my sunflowers tend to move after the petals are open, but maybe untill there are definite seeds formed it could still be considered the bud stage? I do know that when the heads are fully loaded with seeds they tend to bend over and look at the ground (from the weight maybe?).

Guess what I am TOTALLY confused just went out and have one plant with about 5 on it -THEY WERE ALL FACING DIFFERENT DIRECTIONS! I mean completely different views? I am stumped-it wasn't just that plant either they were all doing different directions?

hah!!!....I can just see the look on your face Wolf! I've been that confused before! Join the club, eh?
I wonder if it is overcast up your way and they are all trying to find the sun or something!
Does that "bud stage" mentioned above mean anything to you? Are your flowers budding, or if they are open do you see any seeds forming yet?

Thanks to all of you for your help.

I noticed yesterday that the large sunflowers that have seeds in them, like we eat for feed the birds were facing the east, but the sunflowers (like the daisy flowers) were facing in all directions.

I forwarded the link on to her.

Jan

Yes same with mine -big facing East daisy like all over! Confused -yeah mother nature does that to me sometimes!

I agree with shoe sunflowers always follows the sun

paul

my perennial sunflowers always look south but I'll check later today and see what they do. I'll take out a compass

Ya'll got me peeking at other people's gardens as I drive around (as if I didn't do that before!). If I see sunflowers I'm gonna jump and and take a reading! (Will also take note of any heat/reflection source that may persuade them to look in that direction (i.e., windows, side of a house throwing out heat, etc).

Jan! You see what your grand-daughter has done to all of us!? Be sure to thank her!