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2 years ago I had a patch of blue bells and a patch of white bells in my garden. Last year they were both white bells. This year there is only one patch, white bells. Do blue bells change to white bells without the right food in the earth? Hope someone can put me out of my misery.

 

I know nothing about Bluebells, but I thought I'd throw in this little nugget of info for what its worth.

Some plants produce flowers whose colour acts as a rough indicator of soil pH. I think some hydrangeas can either be blue or pink depending on the acidity of the soil, and Thyme can be white or pink depending on its soil.