Which statement best describes the difference between a complete fertilizer and a starter fertilizer?

• A. A starter fertilizer provides all primary nutrients (N-P-K) and sometimes secondary nutrients; a complete fertilizer is high in phosphorus to promote root development at transplant
• B. A starter fertilizer is high in nitrogen to promote leaf growth
• C. A complete fertilizer provides all primary nutrients (N-P-K) and sometimes secondary nutrients; a starter fertilizer is high in phosphorus to promote root development at transplant
• D. A complete fertilizer is phosphorus-free

Answer: (C)

The main idea here is how fertilizers are formulated for different growth goals. A complete fertilizer contains all three primary nutrients—nitrogen (N), phosphorus (P), and potassium (K)—and often includes secondary nutrients (like calcium, magnesium, sulfur) and sometimes micronutrients. This makes it a general-purpose feed that supports overall plant development.

A starter fertilizer is designed to help establish rooting when plants are transplanted. Its hallmark is a higher phosphorus content, which promotes strong root growth and establishment in the new location. It’s not meant to supply a full balance of NPK for ongoing growth in the same way a complete fertilizer does.

So the statement that matches this distinction—that a complete fertilizer provides all primary nutrients (N-P-K) and sometimes secondary nutrients, while a starter fertilizer is high in phosphorus to promote root development at transplant—best describes the difference.

Some choices are less accurate because they mischaracterize starter as always providing all NPK, or claim a complete fertilizer is phosphorus-free. In reality, starter focuses on phosphorus for roots, while complete fertilizers aim to supply the full range of essential nutrients.