Plant guide:🍅 Tomato
Back to Plant Clinic
Magnesium Deficiency in Tomatoes — tomato plant care
⚠ Minor

Yellowing between distinctly green veins on older leaves — classic interveinal chlorosis from magnesium deficiency.

ðŸĐš
Nutrients

Magnesium Deficiency in Tomatoes

Commonly affects: Solanum lycopersicum (Tomato)

Yellowing appears between the leaf veins while the veins themselves stay distinctly green, starting on older, lower leaves and progressing upward if untreated. Leaf edges may curl slightly upward.

Potential Causes

  1. 1Magnesium-poor soil, common in sandy or heavily leached growing media
  2. 2High potassium fertilisation competing with magnesium uptake
  3. 3Cool soil temperatures reducing root uptake efficiency even when magnesium is present

Solution Steps

  1. 1Apply a diluted Epsom salt solution (1 tablespoon per litre of water) as a foliar spray or soil drench.
  2. 2Repeat every 2 weeks until new growth shows normal green colour.
  3. 3Reduce potassium-heavy fertiliser applications if magnesium deficiency recurs.
  4. 4Incorporate dolomitic lime into soil before planting in known magnesium-poor beds.

Prevention Tip

Epsom salt (magnesium sulfate) is a fast, cheap, and reliable fix — many experienced tomato growers apply it preventively once fruit begins forming.

More Nutrient Deficiencies Problems

See all →
Phosphorus Deficiency — Purple-Tinted Leaves & Stunted Growth — monstera plant care

Phosphorus Deficiency — Purple-Tinted Leaves & Stunted Growth

Zinc Deficiency — Small, Distorted New Leaves & Shortened Internodes — monstera plant care

Zinc Deficiency — Small, Distorted New Leaves & Shortened Internodes

Manganese Deficiency — Young Leaf Interveinal Chlorosis & Pale New Growth — monstera plant care

Manganese Deficiency — Young Leaf Interveinal Chlorosis & Pale New Growth

Boron Deficiency — Deformed New Growth & Hollow Petioles — monstera plant care

Boron Deficiency — Deformed New Growth & Hollow Petioles

See how growers dealt with this →
Track this problem in your grow diary