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Name: Catherine R.
Status: educator
Age: 30s
Location: N/A
Country: N/A
Date: 6/25/2003

Why wont the white flowers on a pansy plant show any sign of absorbing red dye when it is watered with a strong solution of red food colouring for 2 weeks?

I am trying out an experiment to demonstrate osmosis using a control plant and an experimental plant. After two weeks of different treatment,they both look exactly the same. I was hoping that the experiment plant would absorb the red dye and show some red colouring in the veins of its white flower. Is there another way to show this happening using flowering plants?

Probably would work better on cut flowers in water.

Anthony Brach, Ph.D

Whether or not you can dye a flower depends both upon the flower you choose and upon the chemical structure of the dye molecules. Some dyes simply are absorbed by the flower. That appears to be so in your case. Try changing flowers, e.g. a white carnation. The attached web site gives a procedure for carnations:

Try doing a search on the term: "dye flowers" on I think you will find a lot of "hits" and specific instructions.

Vince Calder

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