How to Fertilize Lemon

Citrus x limon

Reviewed by Kiersten Rankel M.S.

Quick Answer

Use a citrus-specific fertilizer with an NPK around 6-4-6 that includes iron, zinc, and manganese. Feed every 4-6 weeks from spring through early fall. Indoor lemon trees can receive light feeding in winter at half strength.

When Should I Start Feeding My Lemon Tree?

Begin feeding when you see new leaf buds in spring, though indoor lemon trees (zones 9a-11b outdoors) may need year-round nutrition since they often grow continuously under bright light.

Pacific Feb–Nov

Mountain May–Sep

Midwest Apr–Oct

Northeast Apr–Oct

Southeast Mar–Nov

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How Often Should I Fertilize My Lemon Tree?

Feed every 4-6 weeks during the growing season. Lemon trees can flower and fruit multiple times per year, so they have higher nutrient demands than most plants.

For indoor lemon trees, continue feeding through winter at half strength every 6-8 weeks. Indoor trees don't fully go dormant under artificial light, and a light feed keeps them producing. For outdoor trees in colder zones, stop feeding in late fall and resume when new growth appears in spring.

Watch for pale leaves, slow growth, or fruit that drops before ripening. These are signs the tree needs more nutrition. Conversely, if you see dark green leaves with burned tips, you're overfeeding.

Feeding Calendar

Spring & Summer

Full-strength citrus fertilizer every 4-6 weeks

Early Fall

Half-strength every 6 weeks, tapering off

Late Fall & Winter

Half-strength every 8 weeks indoors, or no feeding outdoors

What Is the Best Fertilizer for Lemon Trees?

Lemon trees are heavy feeders that need a citrus-specific fertilizer with added micronutrients. Look for a formula with an NPK ratio around 6-4-6 or 5-2-6 that includes chelated iron, zinc, and manganese. Without these, lemon trees develop yellow leaves with green veins, a telltale sign of iron chlorosis.

For potted indoor lemon trees, liquid citrus fertilizer gives you the most control. You can adjust the dose with the seasons and avoid the salt buildup that plagues containerized citrus.

Outdoor lemon trees in the ground can use slow-release citrus granules applied at the start of each season. The granules feed gradually with each watering, which suits the deep root systems of established trees.

Synthetic

Miracle-Gro Citrus, Avocado & Mango Food 6-4-6

Shake-on granular with iron and magnesium. Easy to apply to both potted and in-ground lemon trees every 4-6 weeks.

Southern Ag Citrus Nutritional Spray

Foliar spray that delivers iron, zinc, and manganese directly to leaves. Useful as a supplement when soil feeding isn't correcting chlorosis.

Organic

Espoma Citrus-tone 5-2-6

Granular organic formula with beneficial microbes and extra iron. Apply every 4-6 weeks during the growing season.

Down to Earth Citrus Mix 6-3-3

Organic blend with feather meal, fish bone meal, and kelp for steady, slow feeding. Work into the top inch of soil.

How Do I Fertilize My Lemon Tree?

Water the tree thoroughly first

Drench the soil with plain water before fertilizing. Citrus roots are especially vulnerable to fertilizer burn when the soil is dry.

Measure the citrus formula

Follow the label instructions for your citrus fertilizer. For potted trees, use half the recommended rate. Lemon trees in containers are more sensitive to salt concentration than those in the ground.

Apply around the drip line

For liquid feeds, pour the solution in a ring around the base of the tree, roughly where the outer leaves drip. For granular, scatter evenly under the canopy and water in.

Check for micronutrient deficiency

If new leaves are yellow between the veins after 2-3 weeks of feeding, your formula may lack iron. Apply a chelated iron supplement or switch to a citrus-specific product that includes it.

Flush container soil regularly

For potted lemon trees, run plain water through the pot until it pours from the drain holes every 6-8 weeks. Citrus fertilizers leave salt residue that builds up fast in containers.

Got More Questions?

Can I use banana peels to fertilize my lemon tree?

Banana peels decompose very slowly in soil and don't release meaningful amounts of potassium to a potted tree. They can attract pests and fungus. Use a proper citrus fertilizer that delivers balanced nutrition plus the micronutrients lemon trees depend on.

What happens if I over-fertilize my lemon tree?

Leaf tips and edges burn brown, and you may see white salt crust on the soil surface. In severe cases, the tree drops leaves or fruit. Flush the soil with several rounds of plain water and skip feeding for 6-8 weeks before resuming at a lower dose.

Why does my lemon tree have yellow leaves with green veins?

That's iron chlorosis, one of the most common problems in citrus. It means the tree isn't getting enough iron, either because the fertilizer lacks it or the soil pH is too high. Switch to a citrus-specific fertilizer with chelated iron.

Should I fertilize my indoor lemon tree in winter?

Yes, but lightly. Indoor lemon trees under good light often grow year-round. Feed at half strength every 6-8 weeks through winter. If the tree is in a dim spot and not producing new growth, skip winter feeding entirely.

Is Epsom salt good for lemon trees?

Epsom salt provides magnesium, which lemon trees do need. A tablespoon per gallon applied 2-3 times a year can help if you see yellowing between leaf veins on older leaves. But it's a supplement, not a replacement for complete citrus fertilizer.

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About This Article

Kiersten Rankel M.S.

Botanical Data Lead at Greg · Plant Scientist

About the Author

Kiersten Rankel holds an M.S. in Ecology & Evolutionary Biology from Tulane University. A certified Louisiana Master Naturalist, she has over a decade of experience in science communication, with research spanning corals, cypress trees, marsh grasses, and more. At Greg, she curates species data and verifies care recommendations against botanical research.

See Kiersten Rankel's full background on LinkedIn.

Editorial Process

Fertilizer recommendations verified against Citrus x limon growth data from Greg's botanical database, cross-referenced with USDA hardiness zone data and published horticultural research.

649+ Greg users growing this plant

USDA hardiness zones 9a–11b

Citations:
NC State Extension
Missouri Botanical Garden

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