The plants you cultivate need more than sun and water to thrive. In addition to tender loving care, they need macro- and micronutrients provided in the proper balance. These nutrients occur naturally in soil, but in varying amounts and, in some cases, in varying quality. The appropriate, supplemental application of essential nutrients depends upon what’s present in the soil – and what a particular plant requires.

There generally are two types of nutrients: macro- and micronutrients. Put simply, those considered macronutrients are the elements that plants require in greater quantities than the micronutrients, which, as logic would have it, are those that are required in lesser amounts.

It all seems obvious, but this is why soil testing is critical to determining what’s sufficient, what’s lacking and what needs to be added.

Listed here are the nutrients, along with their basic characteristics or qualities, and general signs of deficiency. This is not intended to be a comprehensive analysis of the nutrients or their effects, but a simple guide to give plant professionals a starting point for further investigation. Soil tests conducted by reliable and reputable labs should be completed prior to application of supplemental nutrients; diagnosis of deficiencies should be confirmed as well. Overapplication of supplemental nutrients can be just as detrimental to plants as deficiency.

Macronutrients

Nitrogen (N), phosphorus (P) and potassium (K) are considered the “primary” nutrients. “Secondary” macronutrients are calcium (Ca), magnesium (Mg) and sulfur (S). Macronutrients are necessary for healthy growth and sustained vigor, but they must be balanced correctly.

The other essentials

We don’t often think of oxygen and moisture as “nutrients.” Without them, of course, plants wouldn’t survive. Structural, or nonmineral, nutrients – carbon (C), hydrogen (H) and oxygen (O) – are obtained from air and water. Each is necessary for the plant to convert into carbohydrates (sugars and starches), which help to build strength in cell walls and to support stems and leaves. Think of these as the most basic plant food.

Micronutrients

Considered “minor” or trace elements, micronutrients include boron (B), chloride (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn). Many support the functions of macronutrients

This is not intended to be a comprehensive analysis of the nutrients or their effects, but a simple guide to give plant professionals a starting point for further investigation. Soil tests conducted by reliable and reputable labs should be completed prior to application of supplemental nutrients; diagnosis of deficiencies should be confirmed as well. Overapplication of supplemental nutrients can be just as detrimental to plants as deficiency.


Nitrogen

  • Essential for plant growth; part of every living cell
  • Necessary for chlorophyll synthesis
  • Directly responsible for increasing protein content in plants
  • Must be present in sufficient amounts to facilitate nutrient uptake

Signs of deficiency:

  • Plant is pale green
  • Lower leaves may appear yellow to brown
  • Symptoms appear first on older leaves, but may then spread throughout the plant

Phosphorus

  • Captures and converts sunlight into essential plant compounds
  • Stimulates root development
  • Promotes improved flower and seed production
  • Promotes increased stalk and stem strength

Signs of deficiency:

  • Plant may appear dark green, with purple or red hues
  • Lower leaves may appear yellow to dark green
  • Symptoms appear first on older leaves, but may then spread
    throughout the plant

Potassium

  • Enhances enzyme actions, aiding in photosynthesis
  • Maintains turgor, reduces water loss
  • Increases root growth, improves drought tolerance
  • Known as “quality nutrient” for overall effects on general plant quality

Signs of deficiency:

  • Leaves appear wilted or scorched
  • Edges or spots on leaf are necrotic
  • Symptoms appear only on olderleaves

Magnesium

  • Captures sun’s energy, facilitating photosynthesis
  • Carries phosphorus; is required for better root formation
  • Mobile within plant; moving from older to younger tissues

Signs of deficiency:

    • Leaf edges appear yellow, but remainder is green
    • Symptoms appear only on older leaves

Calcium

  • Stimulates root and leaf development
  • Affects uptake and activity of other nutrients
  • Helps form compounds that compose cell walls, strengthening plant structure
  • Balances organic acids; activates plant enzyme systems

Signs of deficiency:

  • New leaves appear deformed
  • Left edges and tips are necrotic
  • Terminal bud appears healthy
  • Symptoms appear first on young leaves

Sulfur

  • Critical for photosynthesis and winter hardiness
  • Appears in every cell; required for synthesis of amino acids and proteins
  • Aids in seed production
  • Aids in efficient nitrogen fixation in leguminous plants

Signs of deficiency:

  • Entire leaf appears yellow
  • Yellow coloration may spread toentire plant
  • Symptoms appear first on young leaves

Boron

  • Helps to improve seed set
  • Is a component of cell walls

Signs of deficiency:

  • Terminal bud dies
  • Leaves appear deformed and/or necrotic
  • Symptoms appear first on young leaves

Chloride

  • Supports transport of macronutrients throughout plant
  • Helps plant acclimate to varying water quantities

Signs of deficiency:

  • White, necrotic spots may appear along leaf edges
  • Leaf tips may curl or wilt
  • Symptoms appear first on young leaves

Copper

  • Least mobile of micronutrients
  • Necessary for successful chlorophyll formation

Signs of deficiency:

  • Plant growth appears stunted
  • Leaves discolored, small and deformed
  • Terminal bud appears healthy
  • Symptoms appear first on young leaves

Iron

  • Assists in chlorophyll formation
  • Deficiencies display as chlorosis in leaves

Signs of deficiency:

  • Yellowing between leaf veins
  • Stems do not appear shortened or rosetted
  • Leaves do not develop necrotic spots
  • Symptoms appear first on young leaves

Manganese

  • Assists in chlorophyll synthesis
  • Accelerates germination and maturity

Signs of deficiency:

  • Yellowing between leaf veins
  • Stems appear shortened or rosetted
  • Leaves develop necrotic spots
  • Symptoms appear first on young leaves

Molybdenum

  • Aids in the use of nitrogen
  • Helps convert inorganic phosphorus to organic forms

Signs of deficiency:

  • Mottling and interveinal chlorosis
  • Plant may show overall chlorosis
  • Leaves may curl or cup

Zinc

  • Essential for several metabolic reactions, critical to early growth stages
  • Aids in protein synthesis and growth regulation

Signs of deficiency:

  • Yellowing between leaf veins
  • Stems appear shortened or rosette
  • Symptoms appear first on young leaves