Question
I am in 5th grade and I am doing a science project on plants.  I planted pea plants and I am watering one with coffee.  I have searched the internet with my mom's help for some info on this subject.  Do you have any data that you can share on any effects coffee may have on plants.  So far, my coffee watered plant is the largest!  

Thank You,
Robert King

Answer
Hi Robert,

I don't have any data to give you. However, I do have some information that may be helpful.

Plants can only absorb essential minerals from the soil when the soil pH (acidity) is in the proper range. If the soil is too acidic or too alkaline, the mineral nutrients do not dissolve properly and are unavailable to the plant. When that happens the plant very slowly starts to lose its healthy green color and its vigor.

Coffee is quite acidic. If it is added to the soil over a long period of time (several months or more), then the soil will become too acidic, the minerals will not be absorbed by the roots, and plant will start to exhibit pale green leaves.

Please let me know if any of this is unclear or if you have any additional questions.

Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: [email protected]

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