How can you distinguish drought stress from nutrient deficiency in landscape plants?

• A. Drought shows wilting with dry soil; nutrient deficiency shows chlorosis or necrosis patterns with adequate moisture; confirm with soil and tissue tests
• B. Drought always causes leaf drop
• C. Nutrient deficiency only occurs in sandy soils
• D. They are identical and cannot be distinguished

Answer: (A)

Distinguishing drought stress from nutrient deficiency relies on recognizing how evidence on the plant and the growing medium align with each problem. When water is limiting, the plant wilts and the soil is dry; this turgor loss is the primary clue that irrigation needs to be addressed. If you provide adequate moisture and the plant’s condition improves, drought was likely the issue. In contrast, nutrient deficiency tends to produce specific patterns such as chlorosis (yellowing) or necrosis (dead tissue) that appear even when moisture is sufficient. The pattern of symptoms—which leaves are affected, and whether the yellowing or death follows the distribution expected for mobile nutrients (older leaves) or immobile nutrients (new growth)—helps point to a particular deficiency. To confirm, you can use soil tests to gauge available nutrients and tissue tests to see what the plant is actually taking up, which distinguishes a true deficiency from a water-related problem or other stress.

These ideas explain why the option stating wilting with dry soil signals drought, while chlorosis or necrosis with adequate moisture signals nutrient deficiency—and who to verify with soil and tissue tests—is the best choice. The other statements aren’t accurate: drought doesn’t always cause leaf drop, deficiencies aren’t limited to sandy soils, and the two problems are not indistinguishable.