Mg deficiency in Hydrangea

Mg deficiency in Hydrangea

Login to access our suggested solutions.

Scientific Name
Magnesium (Mg)
Atomic Number
12
Atomic Weight u
24.305
Elemental Group
Meso elements (Ca, Mg, S ) | Secondary macronutrients
Available Forms

Available forms of Magnesium (Mg) for use in Container Nursery Stock

  • Magnesium sulfate (MgSO₄·7H₂O, “Epsom salt”) – highly soluble, quick foliar or substrate correction.
  • Magnesium sulfate monohydrate (MgSO₄·H₂O) – more concentrated, soluble form of magnesium sulfate.
  • Magnesium oxide (MgO) – slow-release, less soluble; suitable for incorporation into media.
  • Dolomitic lime (CaMg(CO₃)₂) – supplies both calcium and magnesium; raises substrate pH slightly.
  • Magnesium carbonate (MgCO₃) – slowly soluble, provides magnesium gradually over time.
  • Magnesium nitrate (Mg(NO₃)₂·6H₂O) – highly soluble, supplies both Mg and N; suitable for fertigation.
  • Magnesium chloride (MgCl₂·6H₂O) – soluble, sometimes used in foliar sprays or hydroponics.

Magnesium (Mg) Deficiency in Hydrangea – Container Nursery Stock

Symptoms

  • Interveinal chlorosis (yellowing between leaf veins) on older leaves first.
  • Leaves may curl or develop necrotic spots if deficiency progresses.
  • Reduced plant vigor and stunted growth.
  • Leaf margins may appear reddish-purple in severe cases.

Causes

  • Low magnesium levels in the growing media or substrate.
  • High potassium or calcium levels that interfere with Mg uptake.
  • Acidic or excessively sandy soils leading to nutrient leaching.
  • Insufficient magnesium in fertilizer regime.

Correction

  • Apply magnesium-containing fertilizers such as magnesium sulfate (MgSO₄·7H₂O, “Epsom salt”) or magnesium oxide (MgO).
  • Foliar sprays with soluble Mg sources for rapid correction.
  • Adjust pH of substrate if it is highly acidic to improve Mg availability.

Prevention

  • Regularly test substrate for nutrient content and pH.
  • Use balanced fertilizers that include magnesium.
  • Avoid excessive application of K and Ca fertilizers that can compete with Mg uptake.
  • Incorporate slow-release Mg fertilizers into the substrate at potting or planting.

Mg deficiency in Hydrangea

Scientific Name
Magnesium (Mg)
Atomic Number
12
Atomic Weight u
24.305
Elemental Group
Meso elements (Ca, Mg, S ) | Secondary macronutrients
Available Forms

Available forms of Magnesium (Mg) for use in Container Nursery Stock

  • Magnesium sulfate (MgSO₄·7H₂O, “Epsom salt”) – highly soluble, quick foliar or substrate correction.
  • Magnesium sulfate monohydrate (MgSO₄·H₂O) – more concentrated, soluble form of magnesium sulfate.
  • Magnesium oxide (MgO) – slow-release, less soluble; suitable for incorporation into media.
  • Dolomitic lime (CaMg(CO₃)₂) – supplies both calcium and magnesium; raises substrate pH slightly.
  • Magnesium carbonate (MgCO₃) – slowly soluble, provides magnesium gradually over time.
  • Magnesium nitrate (Mg(NO₃)₂·6H₂O) – highly soluble, supplies both Mg and N; suitable for fertigation.
  • Magnesium chloride (MgCl₂·6H₂O) – soluble, sometimes used in foliar sprays or hydroponics.
Mg deficiency in Hydrangea

Magnesium (Mg) Deficiency in Hydrangea – Container Nursery Stock

Symptoms

  • Interveinal chlorosis (yellowing between leaf veins) on older leaves first.
  • Leaves may curl or develop necrotic spots if deficiency progresses.
  • Reduced plant vigor and stunted growth.
  • Leaf margins may appear reddish-purple in severe cases.

Causes

  • Low magnesium levels in the growing media or substrate.
  • High potassium or calcium levels that interfere with Mg uptake.
  • Acidic or excessively sandy soils leading to nutrient leaching.
  • Insufficient magnesium in fertilizer regime.

Correction

  • Apply magnesium-containing fertilizers such as magnesium sulfate (MgSO₄·7H₂O, “Epsom salt”) or magnesium oxide (MgO).
  • Foliar sprays with soluble Mg sources for rapid correction.
  • Adjust pH of substrate if it is highly acidic to improve Mg availability.

Prevention

  • Regularly test substrate for nutrient content and pH.
  • Use balanced fertilizers that include magnesium.
  • Avoid excessive application of K and Ca fertilizers that can compete with Mg uptake.
  • Incorporate slow-release Mg fertilizers into the substrate at potting or planting.