Plants just like people need necessary nutrients to live. Without the proper amount of nutrients, plants suffer.

Here is a list of common nutrients, signs of nutrient deficiencies and what to give to make the plant healthy.


Before we jump into nutrients, we need to talk about an essential factor, pH. pH or power of hydronium (H30+) is a measurement of the concentration of hydrogen ions in a liquid. Plants absorb nutrients with charges on them since hydrogen has a positive charge, pH can change how plants absorb nutrients. You may want to check your soil pH to see how it is affecting your plants. For hydroponic systems, the pH can be changed by adding salts to the system.

Control Complete Nutrients. Deficiencies of Magnesium and Iron. Images provided by a Penn State Study, Fall 2012

Macro-nutrients (primary) 

These are the nutrients that plants need in abundance to have healthy growth.


After Hydrogen, Oxygen, and Carbon, Nitrogen is the most abundant element in plants. Nitrogen is needed to make proteins. Because of this nitrogen is the most common plant nutrient deficiency.

Signs of Nitrogen Deficiency:

Stunted grown, yellow leaves.

Solution Nitrogen Deficiency:

Plants can not absorb all forms of nitrogen. Nitrogen gas, N2 makes up most of Earth’s atmosphere, if plants could absorb N2 than Nitrogen deficiencies would be rare, however plants can only absorb nitrate (NO3-) or ammonium (NH4+). Bacteria in the soil can change nitrogen to a form that plants can absorb. Nitrogen is best incorporated in a neutral pH but also depends on which kind of nitrogen compound.


Phosphorus is found in DNA, RNA, cell membranes, and ATP, which stores energy in plant cells. These cell functions make phosphorus an essential plant nutrient.

Signs of Phosphorus Deficiency:

Stunted Plants with dark leaves. Plants will become dark green in color. Temperature can affect how some plants absorb phosphorus. It might be that a plant has enough phosphorus around them, but they can’t uptake it because it is too cold for them.

Solution to Phosphorus Deficiency:

Make sure that your plant’s absorption is not sensitive to temperature, if it is, then you need to raise the temperature in the greenhouse, take the plant inside, or put a plant electric heater on. Plants absorb phosphorus in the form of H2PO4- or HPO42-. Phosphorus is best absorbed in a neutral or mild to strong alkaline, basic pH.


Potassium helps the plant grow and develop. Also, it also helps regulate water levels in the plant. If a plant is deficient in potassium, it will become more susceptible to drought.

Signs of Potassium Deficiency:

Older leaves die, they develop spots of brown or black. In severe deficiencies, leaves of plants will have curled leaves. Stunted plants is another common sign of a progressed deficiency. For some plant species, leaves will turn bronze.

Solution to Potassium Deficiency:

Applying potassium to the plant or the soil. Plants absorb potassium in the form of K+. This means that most potassium salts fertilizers would solve a deficiency. Potassium is not absorbed well in an acidic solution.

Nutrient deficiencies of Potassium, Calcium, Nitrogen, Sulfur. Penn State Testing on Tobacco Plants Fall 2012.

Macro-nutrients (secondary and tertiary)

Second and tertiary macronutrients are not as crucial as primary nutrients, but still, need to be present. If they are entirely lacking, they can cause problems just as the primary nutrients deficiencies do.


Sulfur gives some proteins their shape. Legumes which have a beneficial mutualistic symbiotic relationship with nitrogen-fixing bacteria need higher amounts of sulfur than other plants.

Sign of Sulfur Deficiency:

Plants can move phosphorus around from older leaves to newer leaves; however plants cannot do this for sulfur. This is why signs of sulfur deficiency start on new leaves. A sign is a chlorosis, dead or dying parts on new growth. New growth can be stunted.

Solution to Sulfur Deficiency:

Sulfur is absorbed by plants in the form of sulfate, SO42-. Because of the negative charge, sulfur is not absorbed well in an acidic solution.


In the cells of plants movement of resources of into the cell is often regulated by Calcium. Calcium also regulates the activity of some enzymes.

Signs of Calcium Deficiency:

Signs first seen in young leaves. Leaves become distorted, or curled and develop small spots of a dead leaf. Leaves may become black. Plant growth is also stunted. Flowering is prevented, and bud development inhibited. Calcium deficiency can cause a flower bud to die. Root tips may die. Roots are effected before leaves, but because they are below ground are not noticed.

Solution to Calcium Deficiency:

Plants absorb calcium in the form of Ca+2, and it is best absorbed in a neutral to slightly alkaline pH.


Chlorophyll, the primary pigment in photosynthesis. Magnesium is in the center of the pigment. Without magnesium, plants wouldn’t be green. Chlorophyll would fade showing secondary pigments: yellow and red.

Signs of Magnesium Deficiency:

Signs of this deficiency are often detected later, as plants move magnesium from older leaves to newer leaves if they don’t have enough. New leaves are a priority for the plant, so signs are seen on the older leaves. Old leaves are chlorotic. Areas in between the veins of the leaves stay green while the veins darken and die.

Solution to Magnesium Deficiency:

Plants absorb in the form of Mg2+ and best in a neutral pH environment.


These nutrients are commonly found in most soils. Where do we find deficiencies? In unusual soils, soils that have been depleted from several years of crop harvests, or in hydroponic systems.

Deficiencies of Phosphorus, Micro-Nutrient, Potassium, Calcium. 


Iron is needed for photosynthesis. Iron absorption is affected by temperature and pH. For some plants, cold temperature can prevent iron uptake. While macronutrients are better absorbed in neutral or alkaline pH, Iron is better absorbed in Acidic pH. This is often a problem in hydroponic systems. Systems with a high, alkaline pH to allow other nutrients to be absorbed prevent iron from being absorbed. Often the solution for hydroponic systems is to add more iron. A copper deficiency can also induce an iron deficiency. Just because the plant has enough iron, doesn’t mean it can get it. Temperature, pH, and copper all affect iron.

Signs of Iron Deficiency:

First seen on new growth. Yellowing between the veins of the leaf, while the veins remain green.

Solution to Iron Deficiency:

Plants absorb iron best in a strongly acidic environment. Plants can absorb iron by an active process as Fe2+ or from iron chelate such as ferric EDTA.


This nutrient was a problem for Australia. Australian soils lack molybdenum. Plants only need a small amount. To fix their problem, Australia threw handfuls of molybdenum out of an airplane as the flew. This small amount of molybdenum was enough to improve plants in Australia. Molybdenum is needed to make proteins, fix nitrogen and nitrogen metabolism.

Signs of Molybdenum Deficiency:

Yellowing occurs between veins of the leaves. Yellowing starts with older leaves then spreads to younger leaves. Leaf edge may change color and become scorched.

Solution to Molybdenum Deficiency:

Plants absorbed as molybdate, MoO42-. Best absorbed in neutral to alkaline pH environments.


Boron helps form plant cell walls.

Signs of Boron Deficiency:

The overall size of the plant is reduced, everything shrinks. Leaves become thick and brittle. Leaves may curl and develop yellow spots. Roots grow swollen and change color.

Solution to Boron Deficiency:

Plants absorb Boron in BO3 −3 from HBO3. Best absorbed in strong to mild acidity or in strong alkaline pH. Plants can also absorb Boron in the form of borates, but it slower and less available than HBO3.


Important for photosynthesis. Copper is also part of the process of producing lignin, essential for trees. A rare deficiency, but some soils can cause copper deficiency.

Signs of Copper Deficiency:

Affecting young leaves first. Leaves become dark green and misshapen. Leaves twist and often develop brown spots.

Solution to Copper Deficiency:

Best absorbed as Cu+2 in mild to medium acidic environments.


Manganese is needed in photosynthesis.

Signs of Manganese Deficiency:

Leaves become yellowing between the veins of leaves. Can appear on older or younger leaves. As the deficiency progresses, leaves will begin to lose turgor and droop.

Solution to Manganese Deficiency:

Plants absorb Manganese as Mn +2 ions.


Zinc is needed to transcribe DNA into RNA. Zinc causes the plant to be stunted and have smaller leaves. This process is from auxin, the plant elongation hormone from being oxidized in the absence of Zinc.

Signs of Zinc Deficiency:

Shorter plants with a reduced length between nodes on the stem. Leave size is also reduced. Often leaf edge is distorted. As the deficiency continues, leaf becomes yellow between the veins of the leaf.

Solutions of Zinc Deficiency:

Plants absorb it in Zn+2 in mild to medium acidic environments.


Chlorine is needed to regulate water in the plant and photosynthesis.

Signs or Chlorine Deficiency:

Leaves wilt and become yellow or necrotic. Roots are stunted and thicken near the tips.

Solution to Chlorine Deficiency:

Applying Cl- to the plant or soil.

Do your plants have some of the signs above? Have you figured out which one? Hopefully, now you can help your plant.

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