Crocus in the Dark
A crocus in bloom
(early spring flower outdoors, or you can purchase one in a flower shop)
Shoe box or other
container that will fit over it and block the light
On a sunny day in the spring, go
outside and look carefully at the petals of a crocus (pronounced CROW cuss).
Notice how far apart the petals are, and what you can see on the inside of the
Now, carefully cover the crocus with
the shoe box or other container. It should be opaque - light shouldn't be able
to shine through it at all.
Wait five minutes. Do something else
while you wait!
Then come back and when all the
children are watching, remove the box.
What has happened?!? The crocus has
closed up into a tight bud. The petals that used to be wide open are now shut
Why? Because crocus flowers are very
sensitive to light. When the box shut out the light, the crocus thought it was
night time. It takes less energy for a plant to be closed than to keep its
petals stretched out, so when it's night time, the crocus closes its petals.
We know that flowers need light to
make their own food and to grow. They also need a little water - usually, rain,
or the water their human friends give them. And they need good soil in which to
grow. But of all of these, light may be the most important - and it's FREE!
Now YOU try being a crocus. Stand with
your arms out at your sides for as long as you can, before it doesn't feel good
any more. Gee - our little friends the crocuses do that ALL DAY LONG!!!!!