Epsom Salt for Meyer Lemon: Recipe, Benefits, and Cautions

Sheryl in Zone 5 grows a container Meyer lemon. She's been spraying foliage with Epsom salt solution twice monthly since May. The tree has three large lemons and many flowers at just 3 feet tall. She wants the correct dilution ratio.

Why Epsom Salt?

Epsom salt (magnesium sulfate) supplies magnesium, a vital micronutrient. Magnesium is central to chlorophyll — it keeps leaves green and enables photosynthesis. Deficiency shows as yellowing between leaf veins on older leaves.

Common Recipe

1 tablespoon (15 ml) per gallon (3.8 L) of water, or 1.5 teaspoons per half gallon. Apply as a foliar spray or soil drench once a month during active growth.

Important Cautions

• Not a complete fertilizer: Magnesium is just one nutrient. You still need a balanced fertilizer (e.g., 15-30-15) with micronutrients. Most quality citrus fertilizers already contain magnesium — check the label.
• Toxicity risk: Excess magnesium can interfere with calcium and potassium uptake. Don't overdo it.
• Occasional use is fine: A monthly foliar spray won't hurt and can green up foliage if magnesium is low.

Best Practice

Use a complete citrus fertilizer as your primary feeding. Reserve Epsom salt for a mid-season boost if leaves show interveinal chlorosis. Your tree's heavy flowering and fruiting suggest it's already well-fed — keep doing what works!