Calcium Deficiency in Plants | Symptoms, Causes & Solutions

Calcium (Ca2+) is an essential plant nutrient vital for healthy growth, cell division, and structural integrity. Despite often being present in soil, many crops suffer from calcium deficiency due to limited mobility within the plant. Understanding how calcium works, recognising deficiency symptoms, and correcting them quickly is key to achieving optimum yield and crop quality.

What Does Calcium Do in Plants?

Calcium plays a central role in cell wall formation, enzyme activation, and root and shoot development. It strengthens plant tissues both above and below ground, helping crops maintain structure and resist stress.
Adequate calcium levels ensure:

Strong cell walls and firm tissues
Healthy root and shoot tips
Improved fruit quality and shelf life
Enhanced resistance to disease and stress

Calcium also supports enzyme systems that promote growth and stimulate the plant’s natural immune responses. When levels are low, plants lose vigour, develop slowly, and become more susceptible to stress and disease.

Foliar calcium products have been shown to improve calcium translocation to active growing points, supporting cell division, enzyme activation, and overall plant structure, as demonstrated by OMEX calcium fertiliser trial results.

Calcium nutrient deficiency symptoms in parsley — Calcium deficiency symptoms in parsley

What Causes Calcium Deficiency in Plants?

Calcium deficiency can occur even when soils contain sufficient calcium. The problem usually lies in uptake and transport, not total availability.
Common causes include:

Restricted root growth due to poor soil structure or waterlogging
Dry or hot conditions, high humidity, or strong winds reducing calcium movement
Excessive nitrogen or potassium fertiliser, which inhibits calcium uptake
Rapid plant growth, increasing demand beyond supply

Because calcium is immobile in plant tissue, new growth often suffers first.

Calcium Deficiency Symptoms in Plants

Calcium deficiency symptoms typically appear in young, rapidly expanding tissues such as new leaves, root tips, and developing fruits.

Common visible signs include:

Leaf tip burn and marginal scorch
Blossom end rot on tomatoes, peppers, or melons
Necrosis of growing points where meristems fail to expand
Soft, deformed, or stunted fruit and roots

These symptoms often worsen during periods of rapid vegetative growth or environmental stress.

Calcium deficiency in strawberries ‘tip burn’, which appears as browning and crinkling at the edge of young leaves.

Crop-Specific Calcium Deficiency Symptoms

Berries and Soft Fruit

In strawberries and other berries, calcium deficiency often shows as ‘tip burn’ – browning and crinkling of young leaves. Severe cases can cause death of the growing point and brown lesions on leaf stalks.
Calcium levels in fruit tend to decline as maturity approaches, reducing firmness and storage life, particularly important for export crops.

Common disorders:

Leaf tip burn
Stunted roots
Reduced storage quality

Discover how targeted calcium nutrition can boost fruit quality and storage life in crops like blueberries.

Pome Fruit (Apples and Pears)

Calcium deficiency in apples and pears causes several post-harvest and storage problems including:

Bitter pit
Cork spot
Watercore
Lenticel blotch pit
Physiological breakdown

These issues are most common in hot, dry conditions or during rapid growth. Maintaining sufficient calcium levels is crucial for high yields and long-term storage quality.

Leafy Vegetables (Lettuce, Endive, Brassicas, Celery & Chicory)

Low calcium levels can lead to leaf cupping, tip burn, and blackening of young leaves. Severe cases may affect 100% of a crop – particularly lettuce, which is very sensitive.
Specific disorders include:

Internal browning in Brussels sprouts
Blackheart in celery and chicory

Adequate calcium is essential for firmness, transport durability, and shelf life. Research also shows that higher calcium levels in lettuce increase resistance to Botrytis cinerea.

Potatoes

Calcium strengthens cell walls and reduces mechanical damage during harvest and storage. It also helps activate enzyme systems and improve natural resistance to disease.

Deficiency may cause:

Weak cell walls leading to breakdown in store
Greater susceptibility to blight and fungal infections
Increased Internal Rust Spot and Hollow Heart

For example, CalMax foliar calcium has been shown to increase marketable tuber numbers and yield in potatoes by over 15%, while helping prevent calcium-related disorders like Internal Rust Spot.

Tomatoes, Peppers, Cucumbers & Melons

Low calcium levels cause blossom end rot, one of the most economically damaging calcium disorders. It results from poor calcium transport to developing fruit under conditions of water stress or rapid growth.

Other symptoms include:

Leaf cupping in seedlings
Reduced tip growth
Root tip death
Soft, sunken lesions on fruit

Grapes and Other Crops

In grapes, stem necrosis occurs when calcium and magnesium levels are low. Affected tissue often becomes infected with Botrytis cinerea.

Other crop disorders include:

Cork spot in pears
Premature fruit abortion in citrus
Pulp spot in avocados
Tissue collapse in beans and peas
Node splitting in carnations and ornamentals

How to Prevent and Correct Calcium Deficiency

Preventing calcium deficiency requires both soil management and timely foliar feeding. Because calcium moves mainly in the xylem and is not easily redistributed within the plant, maintaining a consistent supply during growth is essential.

Check Soil Calcium Status Regularly test soil and adjust calcium levels where necessary. Acidic soils can reduce availability, so liming or gypsum may help maintain optimum balance.
Promote Healthy Root Growth Strong roots are vital for calcium uptake. Maintain good soil structure and ensure adequate phosphorus and zinc to support root development.
Avoid Nutrient Imbalances High levels of nitrogen or potassium can restrict calcium uptake. Use balanced fertiliser programs to prevent competition in the root zone.
Manage Water and Stress Calcium uptake depends on transpiration. Irregular watering, drought, or high humidity can quickly lead to deficiency symptoms. Keep moisture levels even and avoid root stress.
Use Foliar Calcium During Critical Periods Applying foliar calcium, such as OMEX CalMax, during periods of rapid growth or heat stress helps maintain supply to developing tissues and prevents disorders like tip burn, internal browning, and blossom end rot.

Consistent calcium management supports strong cell walls, better fruit firmness, and improved shelf life, protecting both yield and market value.

Managing Stress to Improve Calcium Uptake

Calcium deficiency is often triggered or intensified by plant stress rather than a lack of calcium in the soil. Heat, drought, rapid growth, and restricted root activity can all reduce calcium movement to developing tissues. Supporting crops during these high-stress periods is essential to maintain calcium uptake and prevent disorders. Targeted nutrition strategies that reduce stress and improve nutrient transport can help safeguard yield and crop quality, as outlined in this guide to preventing calcium deficiency under stress conditions.