Most plants prefer soil pH in which range?

• A. 4 to 6
• B. 5 to 8
• C. 6 to 9
• D. 3 to 5

Answer: (B)

Soil pH controls nutrient availability in the root zone. Most plants grow best when the soil is mildly acidic to near neutral, roughly in the 5 to 8 range. In this window, a wide array of nutrients stay soluble enough for uptake, and toxicities are less likely. If the pH drops below about 5, some nutrients become overly available or certain elements reach toxic levels, while others become less available; if the pH rises above about 8, micronutrients like iron, manganese, and zinc become poorly soluble and limit growth. The 5–8 window captures the balance for a broad variety of species, whereas the more acidic range (4–6) or the more alkaline range (6–9) can create nutrient limitations for many plants. Therefore, 5 to 8 is the best general range.