Growing kale crop nutrition advice

Everything you need to know about fertilising kale, best practice, suitable products, field trials and more.

Nutrition advice for growing Kale

  • Kale generally performs best in slightly acidic to neutral soil with a pH level ranging from 6.0 to 7.5

  • Kale typically thrives in loamy soil, which is a mixture of sand, silt, and clay

  • Kale grows best in cool temperatures, typically between 15°C and 24°C

  • Kale is a sun-loving crop that thrives in full sun. It typically requires at least 6 to 8 hours of direct sunlight per day to grow and develop optimally.

  • Kale crops generally require consistent moisture to thrive, but they are relatively tolerant of dry conditions once established.

  • Kale requires a balanced intake of nutrients to ensure healthy growth, robust fruit development, and disease resistance.

The Significance of Kale

Kale holds a significant position in the agricultural landscape of the United Kingdom, valued for its nutritional richness, versatility, and contribution to sustainable farming practices. As a nutrient-dense leafy green crop, kale plays a vital role in promoting human health and well-being. It offers an abundance of vitamins, minerals, and antioxidants, making it a valuable component of a balanced diet. Additionally, kale’s robust growth and resilience make it an ideal candidate for sustainable farming systems, contributing to soil health and biodiversity.

The extent of Kale Cultivation in the UK

The UK cultivates a substantial area of land dedicated to kale farming, with hundreds of hectares under cultivation annually. This extensive cultivation underscores the importance of kale in meeting the demands of various sectors, including fresh produce markets, food processing companies, and the health food industry, which heavily rely on kale as a primary ingredient in their products, ensuring a reliable supply chain for the agricultural industry.

What are the Nutrient Requirements of kale?

Kale crops have specific nutrient requirements, primarily needing nitrogen, phosphorus, and potassium for optimal growth and yield. Nitrogen is crucial for promoting leafy growth and enhancing overall plant vigour. Phosphorus supports root development and flowering, while potassium contributes to disease resistance and stress tolerance.

 

What are the roles of nutrients in kale?

  • Nitrogen (N): Essential for leafy growth and overall plant vigor, nitrogen is crucial for the production of chlorophyll and proteins in kale plants.
  • Phosphorus (P): Important for root development, flowering, and fruiting in kale plants. Phosphorus also plays a role in energy transfer and the formation of DNA and RNA.
  • Potassium (K): Necessary for overall plant health and stress tolerance, potassium helps regulate water uptake, nutrient transport, and enzyme activation in kale plants.
  • Calcium (Ca): Essential for cell wall structure and integrity, calcium helps prevent disorders like tip burn and ensures proper nutrient uptake and plant stability.
  • Magnesium (Mg): An integral component of chlorophyll, magnesium is essential for photosynthesis and energy production in kale plants. It also plays a role in enzyme activation and nutrient uptake.
  • Sulphur (S): Necessary for the synthesis of amino acids and proteins, sulphur contributes to kale plant growth and development. It also plays a role in the formation of certain vitamins and enzymes.
  • Micronutrients: Kale plants also require small amounts of micronutrients such as iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), and molybdenum (Mo) for various physiological processes and enzyme functions.

 

What are the deficiencies & issues that can be faced when growing kale?

When cultivating kale crops, several common nutrient deficiencies and issues may arise, impacting plant health and yield potential. Nitrogen deficiency may result in stunted growth and yellowing of leaves, starting from the older bottom leaves, and progressing upwards. Phosphorus deficiency can manifest as slow growth and purplish discoloration on leaves, particularly along the leaf margins. Potassium deficiency may cause leaf curling, necrosis, and reduced resistance to pests and diseases. Additionally, kale crops are susceptible to pests like aphids and diseases such as downy mildew, which can affect foliage quality and overall yield. Implementing proper soil fertility management practices and disease prevention strategies is essential for mitigating these issues and ensuring healthy kale crop growth.

 

NutrientDescription
Nitrogen DeficiencySymptoms include overall stunted growth, yellowing (chlorosis) of older leaves, and reduced yield. Leaves may appear pale green or yellow, starting from the older bottom leaves and progressing upwards.
Phosphorous DeficiencyManifests as slow or stunted growth, purplish discoloration of leaves, particularly along leaf margins or between veins. Poor root development and delayed maturity may also occur, leading to reduced yield.
Potassium DeficiencyLeads to yellowing or browning of leaf edges (necrosis), weak stems, and increased susceptibility to diseases. Symptoms may include leaf curling and overall reduced plant vigour.
Calcium DeficiencyCauses disorders like tip burn, characterized by darkened or necrotic leaf edges or tips. Affected leaves may exhibit distorted growth or show signs of decay, reducing overall yield and quality.
Magnesium DeficiencySymptoms include interveinal chlorosis in older leaves, where leaf tissue between veins turns yellow while veins remain green. Reduced chlorophyll production and impaired photosynthesis may result in overall plant weakness.
Sulphur DeficiencyLeaves exhibit general yellowing, particularly in younger leaves, due to a lack of chlorophyll production. Growth may be stunted compared to healthy plants, and overall plant vigour may decline.

 

How can I spot Nutrient Deficiencies in kale?

Detecting nutrient deficiencies in kale crops requires careful observation of plant symptoms and understanding their underlying causes. Regular scouting of kale fields, coupled with soil testing and nutrient monitoring, aids in early detection and intervention. Symptoms of nitrogen deficiency include pale green or yellowing leaves and stunted growth, while phosphorus deficiency may lead to purplish discoloration on leaves and slow growth. Potassium deficiency presents as leaf curling, necrosis, and reduced plant vigour. Pests and diseases such as aphids and downy mildew can also be identified through visual inspection of plants. Prompt intervention with appropriate corrective measures helps mitigate deficiencies and ensure optimal kale crop health and productivity.

 

What are the different Species of Trees Commonly Grown in Forestry in the UK?

Common varieties of kale grown in the UK include Curly Kale, Red Russian Kale, and Lacinato Kale. These varieties are chosen for their adaptability to UK growing conditions, flavour profiles, and culinary versatility, offering a range of options for farmers and consumers alike.

 

Use of ICL’s Products such as Polysulphate in Forestry

ICL’s products, like Polysulphate, play a crucial role in optimising kale cultivation. Polysulphate, with its balanced composition of essential nutrients, including sulphur, potassium, magnesium, and calcium, supports healthy kale growth and development. The controlled release of nutrients ensures a steady supply throughout the growing season, promoting robust plant growth, improved disease resistance, and enhanced yield potential. Integrating Polysulphate into kale cultivation practices can lead to increased productivity, better quality kale, and sustainable agricultural practices, aligning with the goals of modern farming operations.

Q&A

Here are some frequently asked questions we received from farmers regarding growing kale

  • The best time to plant kale depends on your climate. In cooler regions, plant kale in early spring or late summer for a fall harvest. In warmer regions, plant kale in the fall for a winter harvest. Kale thrives in cooler temperatures and can withstand light frost.

  • Kale plants require consistent moisture, especially during the growing season. Water deeply whenever the top inch of soil feels dry to the touch, typically about once or twice a week depending on weather conditions. Avoid overwatering, as kale plants can develop root rot in waterlogged soil.

  • A balanced fertilizer with a ratio of 10-10-10 or similar (N-P-K) is suitable for kale. Apply fertiliser before planting and side-dress during the growing season.

  • Practice crop rotation to prevent the build-up of pests and diseases in the soil. Keep the garden area clean and free of debris to discourage pest infestations. Additionally, monitor plants regularly for signs of pests such as aphids or cabbage worms, and use organic pest control methods like handpicking or applying neem oil.

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