Nutrient deficiencies in plants will reduce their chances of flourishing. Not only will growth, health and vigour be thwarted, an imbalance can worsen attack from pests and diseases.
The earlier you can identify various symptoms in leaves and stems and then correct the availability of any deficiencies, the better your chance of impressive results and yields.
Did you know leaf yellowing can have multiple causes? Where yellowing appears — on older or newer leaves — or its pattern, reveals key clues. Understanding the different signs enables targeted interventions. Read on to improve your diagnosis and transform your plants vibrancy...
Common Nutrient Deficiencies and Their Symptoms:
Just like humans need a balanced diet to stay healthy, plants require a balanced mix of nutrients to grow strong, resist diseases and produce high-quality stems, foliage, flowers & fruit. When one or more essential nutrients are lacking, plants commonly show visible symptoms—often in their leaves, stems, or overall growth pattern.
Understanding Plant Deficiencies
Nutrient deficiencies don’t always look the same, and their symptoms can often be mistaken for disease, environmental stress, or improper watering. However, once you know what to look for, you can diagnose and correct deficiencies before they significantly impact plant health and productivity.
Some of the most common symptoms include:
- Yellowing (Chlorosis) – A sign of nutrient imbalance, often caused by nitrogen, iron, or magnesium deficiencies.
- Leaf Browning or Dry Edges – Can indicate potassium or copper deficiency, or drought stress.
- Purple or Reddish Discolouration – A common sign of phosphorus deficiency.
- Slow Growth & Weak Stems – Often linked to low nitrogen, phosphorus, or calcium levels.
- Distorted or Deformed Leaves – May suggest deficiencies in boron, calcium, or zinc.
By understanding these early warning signs, growers can take action before deficiencies affect yield, flower production, or overall plant vitality. In the sections below, we’ll break down specific nutrient deficiencies, their symptoms and how to correct them for optimal plant health.
Nitrogen (N) Deficiency:
- Symptoms: Yellowing of older leaves (chlorosis), stunted growth and reduced yield.
- Visual Indicator: Uniform yellowing starting from the leaf tips, progressing along the midrib and lighter green of upper (younger) leaves. Not to be mistaken with naturally occurring Autumnal leaves
Phosphorus (P) Deficiency:
- Symptoms: Dark green or purplish coloration of older leaves, delayed maturity and poor root development.
- Visual Indicator: Purpling of leaf undersides and stems.
Potassium (K) Deficiency:
- Symptoms: Yellowing or browning at leaf edges (marginal scorch), weak stems and increased susceptibility to disease.
- Visual Indicator: Chlorosis along leaf margins leading to necrosis.
Boron (B) Deficiency:
- Symptoms: Brittle, discoloured leaves, hollow stems and poor fruit or seed development.
- Visual Indicator: Thickened, curled and wilted young leaves.
Calcium (Ca) Deficiency:
- Symptoms: Deformed or necrotic young leaves, blossom end rot in fruits and poor root development.
- Visual Indicator: New leaves are distorted or hook-shaped.
Copper (Cu) Deficiency:
- Symptoms: Stunted growth, reduced flowering and fruiting, dieback of stems and tips. Chlorosis of younger leaves, tips and edges brown.
- Visual Indicator: Young leaves may appear bluish-green, become limp or wilted, with tips that dry out or curl downward.
Iron (Fe) Deficiency:
- Symptoms: Interveinal chlorosis on new leaves, leading to pale or yellow leaves.
- Visual Indicator: Yellowing of young leaves while veins remain green.
Magnesium (Mg) Deficiency:
- Symptoms: Interveinal chlorosis (yellowing between veins) on older leaves, leading to leaf drop.
- Visual Indicator: Green veins with yellowing between them.
Manganese (Mn) Deficiency:
- Symptoms: Interveinal chlorosis on young leaves, grey speck disease in oats.
- Visual Indicator: Yellowing between veins of young leaves with brown spots.
Molybdenum (Mo) Deficiency:
- Symptoms: Pale or yellowing older leaves, twisted or cupped leaf edges and poor flower or fruit development. In brassicas, it may cause “whiptail” where leaves become narrow and distorted.
- Visual Indicator: Yellowing of older leaves with leaf margins curling or narrowing—especially noticeable in cauliflower and other brassicas.
Sulphur (S) Deficiency:
- Symptoms: Uniform yellowing of young leaves, similar to nitrogen deficiency but affects newer growth.
- Visual Indicator: Pale yellow new leaves with stunted growth.
Zinc (Zn) Deficiency:
- Symptoms: Shortened internodes, rosetting of leaves, and interveinal chlorosis.
- Visual Indicator: Small, distorted leaves with yellowing between veins.
Diagnostic Tips:
- Leaf Position Matters: Deficiencies in mobile nutrients (e.g., nitrogen, phosphorus, potassium) typically show symptoms in older leaves first, while immobile nutrient deficiencies (e.g., calcium, sulphur, iron) appear in newer growth.
- Pattern Recognition: Interveinal chlorosis (yellowing between veins) often indicates deficiencies in nutrients like magnesium or iron.
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Comprehensive Assessment: Environmental factors can greatly influence nutrient availability and uptake. Consider these key points:
- Low pH (acidic): Can lead to deficiencies in phosphorus, calcium, magnesium and molybdenum.
- Excessive acidity (really low pH): Can cause toxicity of elements like aluminium and manganese.
- High pH (alkaline): Can lead to deficiencies in several micronutrients including iron, manganese, boron, copper and zinc.
- Excessive alkalinity (really high pH): Can also cause phosphorus to become unavailable as it binds with calcium.
- Soil moisture: Is an important for nutrient availability, as it influences the dissolution and movement of nutrients, impacting plant uptake and growth. Adequate moisture allows nutrients to dissolve and move through the soil, while dry conditions can limit nutrient availability. Similarly, too much moisture reduces oxygen in the soil, retards important microbes and limits roots ability to absorb nutrients.
- Other Factors: Environmental stress (e.g., heatwaves, pests) or seasonal shifts (e.g., early autumn signs) may mimic or worsen deficiency symptoms.
Visual Aid:
For detailed visual guide to nutrient deficiencies, download our 2 visual guides below:
Ready to Grow Like a Pro?
Spotting nutrient deficiencies early is key to growing stronger, healthier plants. Regular observation, supported by soil testing and smart fertiliser choices, helps you stay on top of your plant’s needs. If testing isn’t an option, use a well-rounded fertiliser like UGF6in1 to ensure your plants get a broad spectrum of essential nutrients.
Noticed signs like yellowing or poor growth? Use our free downloads and bookmark this blog so you’ve always got a go-to guide when something doesn’t look quite right.
