Here is a short list of organizations where schools and other non-profits can apply for gardening grants. I would suggest checking locally first. You might find your local Optimist Club would be excited to help fund a Tower Garden in your classroom.
K21 Health Foundation
August 1, February 1, May 1
May support 1 Tower Garden, but like ‘district-wide solve’ Work together with your school district.
Will want school administration involved.
Crown Point Community Foundation
Marshall County Community Foundation
Community Foundation of Elkhart County
Superintendent must approve application
Whole Kids Foundation