Plant guide:🍅 Tomato
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⚠ MinorYellowing between the veins on older leaves � a classic sign of magnesium deficiency in heavy-feeding tomato plants.
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Nutrients
Yellowing Leaves � Nutrient Deficiency in Tomatoes
Commonly affects: Solanum lycopersicum (Tomato)
Older, lower leaves turn pale yellow or develop yellowing between the veins while the veins themselves stay green, depending on which nutrient is short. Growth may also slow overall.
Potential Causes
- 1Nitrogen deficiency, causing uniform yellowing that starts on older leaves
- 2Magnesium deficiency, causing yellowing specifically between the veins (interveinal chlorosis) on older leaves
- 3Potassium deficiency, often showing as yellowing and browning along leaf edges
- 4Depleted container soil that hasn't been fed in several weeks
Solution Steps
- 1Apply a balanced tomato-specific fertiliser, since these are formulated for the nutrient ratios tomatoes need most.
- 2For suspected magnesium deficiency, apply a diluted Epsom salt foliar spray or soil drench.
- 3Feed container-grown tomatoes every 1�2 weeks during fruiting, since frequent watering leaches nutrients quickly.
- 4Mulch to help retain nutrients and moisture in garden beds.
Prevention Tip
Use a tomato-specific fertiliser formulated with the calcium, magnesium, and potassium ratios these heavy-feeding plants need, rather than a generic all-purpose feed.
