Magnesium deficiency citrus trees show a clear pattern of yellowing between the leaf veins while the veins stay green. This symptom starts on older leaves first and spreads upward if you do not fix it. The citrus leaf symptoms look different from other problems so you can spot them once you know what to look for.
I found this exact pattern on my Meyer lemon last summer. The older leaves near the bottom showed a V-shaped yellow patch spreading from the leaf tip toward the stem. New growth at the branch tips looked fine with dark green color. This contrast told me the tree was moving magnesium from old leaves to feed the new ones.
Your tree does this because magnesium moves freely inside the plant. When supplies run low, the tree pulls this nutrient from older leaves and ships it to new growth. This keeps young leaves healthy but leaves the older foliage starving for what it needs to make chlorophyll.
Citrus yellow leaves from magnesium shortage have a unique look. The tissue between veins turns pale yellow or lime green. The veins themselves stay dark green and stand out against the faded background. You might also see bronze or purple tints on leaf edges as the problem gets worse.
Other citrus nutrient problems can look similar at first glance. Iron deficiency also causes yellowing but it hits new leaves first rather than old ones. Nitrogen shortage makes the whole leaf turn pale yellow without the green vein pattern. Knowing these differences helps you pick the right treatment.
Magnesium Shortage
- Leaf location: Shows up on older leaves at the bottom of your tree first then moves upward over time.
- Color pattern: Yellow between veins while veins stay green, often in a V-shape from leaf tip.
- Edge symptoms: Bronze or purple tinting may appear along leaf margins as the problem advances.
Iron Shortage
- Leaf location: Appears on newest leaves and young growth at branch tips first.
- Color pattern: Yellow between veins similar to magnesium but on new growth rather than old.
- Edge symptoms: Leaf edges may curl or become papery thin in severe cases.
Nitrogen Shortage
- Leaf location: Starts on older leaves but affects the whole canopy as it worsens.
- Color pattern: Entire leaf turns pale yellow-green without distinct vein patterns showing.
- Edge symptoms: Leaves may drop early and tree growth slows down across all branches.
A soil test costing $15-30 confirms what your tree needs. The test shows magnesium levels along with pH and other nutrients. High pH above 7.0 can lock up magnesium even when the soil has plenty. Sandy soils also lose magnesium fast from rain and irrigation washing it away.
You can fix this problem with Epsom salt or chelated magnesium. Mix 1 tablespoon of Epsom salt per gallon of water for a foliar spray. You should see green color return within 2-4 weeks of treatment. Repeat the spray monthly during growing season to keep the problem from coming back.
Read the full article: Citrus Tree Care: Essential Guide for Growers
