order the topics from broadest to narrowest. broader unusual gardening techniques the role of nutrients in…

Brief Explanations:

"Unusual gardening techniques" is a broad - category term that can cover many different types of non - traditional gardening methods. "The role of nutrients in soil - less gardening" is more specific as it focuses on a particular aspect (nutrients) within a specific type of gardening (soil - less). "Cultivating plants in water instead of soil" is the most narrow as it describes a very specific technique within soil - less gardening.

Answer:

unusual gardening techniques, the role of nutrients in soil - less gardening, cultivating plants in water instead of soil