Sentence 3 is off-topic.
The rough-draft paragraph is about the therapeutic well-being that gardening can have. While the second sentence mentions that the organic fruits and vegetables are organic, it goes on to mention metal benefits of gardening. However, sentence three does not talk about any mental benefits, but rather talks about how the gardeners can decide if pesticides will be used or not. While this does relate to organic fruits and vegetables, it is not related to the main idea of the paragraph.