Contributor: J.R. Baker, Extension Entomology Specialist
Sixteen elements are essential for plant growth. These are divided into two groups based on the amount of each needed by plants. The nine macro nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, carbon, hydrogen, and oxygen) are required in relatively large amounts. Of these, nitrogen, phosphorus, and potassium are the elements most commonly added as fertilizer.
The seven micro nutrients (iron, manganese, zinc, boron, molybdenum, copper, and chlorine) are required in smaller amounts. Iron and manganese are the micro nutrients most often deficient in landscape plants. An adjustment in soil pH usually corrects deficiencies of the micro nutrients.
Each of these 16 elements plays a specific role in plant growth. A deficiency or an excess of any one of them will impair plant growth until the problem is corrected. Evaluating plant growth, testing the soil, and analyzing the plant tissue are ways to assess nutrient needs. Contact the agencies listed below for instructions on sample collection for analysis of nutrient deficiencies.
Table 1. Signs of Nutrient Deficiency in Woody Plants
(Source: Pennsylvania Cooperative Extension Service)
| Element | Foliar Symptoms |
| Nitrogen (N) | General yellowish-green; more severe on older leaves. Stunted growth; small, fewer leaflets; early leaf drop. |
| Phosphorus (P) | Dark green to blue-green, slightly smaller leaves. Veins, petioles, or lower surface may become reddish-purple, especially in the case of young leaves; death of lower needles in pines. |
| Potassium (K) | Partial chlorosis (yellowing) of most recently matured leaves in interveinal area beginning at tips, followed by necrosis (tissue death). Older leaves may become brown and curl downward. |
| Calcium (Ca) | Death of terminal buds, tip dieback, chlorosis of young leaves; leaves may become hard and stiff. Root injury is the first apparent sign. |
| Magnesium (Mg) | Marginal chlorosis on older leaves followed by interveinal chlorosis. Tips and margins may become brittle and curl upward. |
| Sulfur (S) | Uniform chlorosis of new leaves; older leaves usually are not affected. |
| Iron (Fe) | Interveinal chlorosis of young leaves (sharp distinction between green veins and yellow tissue between veins). Older basal leaves greener; exposed leaves blanched. |
| Manganese (Mn) | Interveinal chlorosis of young leaves beginning at margins and progressing toward midribs, followed by necrotic spots. |
| Zinc (Zn) | Young leaves may be yelIow, small, deformed, or mottled with necrotic spots. There may be a tuft of leaves at shoot tips. |
| Boron (B) | Terminal growth dies; later growth that develops has sparse foliage. Young leaves may be red, bronzed, or scorched. Leaves may be small thick, distorted, or brittle. |
| Copper (Cu) | Rosetting of terminal growth may die. Leaf symptoms not usually pronounced, but veins may be lighter than blades. |
| Molybdenum (Mo) | Cupping of the older leaves; marginal chlorosis followed by interveinal chlorosis. |
Soil Test for Nutritional Levels:
Plant (foliar tissue) Analysis for Nutritional Levels:
Return to Identifying Plant Problems