Fertilizing a Citrus Tree: What Month, How Much, & Best Ratios

Co-authored by Matt Bowman and Janice Tieperman

Last Updated: December 26, 2022 References

Have you ever wanted to grow a lemon or orange tree at home? These plants are pretty easy to care for, but they need a lot of fertilizer so they can grow up strong and healthy. Not to worry—we’ve answered all your frequently asked questions, so you can put your best foot forward during the next growing season!

Question 1 of 6:

How often should you fertilize citrus trees?

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Fertilize your tree throughout the year when you first plant it. Nourish your tree once every 1-2 months when the tree is actively growing. When your tree goes through a dormant period, or a time when it stops growing, fertilize it once every 3 months.^{[1]
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Nourish your tree throughout the growing season when it starts producing fruit. Unfortunately, there isn’t a one-size-fits-all recommendation for citrus trees—it really depends on when you live. Most experts agree that you should feed your citrus tree multiple times during the growing season, so it gets plenty of nutrients.^{[2]
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- The “growing season” is whenever your citrus tree produces fruit.^{[3]
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- In a dry, hot climate, fertilize your citrus tree on Valentine’s Day (February 14), Mother’s Day (second Sunday in May), and Father’s Day (third Sunday in June).^{[4]
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- If you’re growing your citrus indoors, fertilize it between mid-spring and late summer/early autumn.^{[5]
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Question 2 of 6:

What is the best fertilizer for citrus trees?

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Take a soil test to see what your tree’s needs are. Unfortunately, there isn’t a universal fertilizer recommendation for citrus trees, since citrus trees can be grown in different climates. Conduct a soil test to see what nutrients your tree is lacking.^{[6]
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Expert Source

Cory Schifter
Jeweler & Certified Jewelry Appraiser
Expert Interview. 21 April 2020.}^{[7]
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- You can buy a soil test online, or from a home improvement store.
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Pick a fertilizer based on the NPK recommendation in your test results. Your NPK ratio, or Nitrogen-Phosphate-Potash ratio, describes what percentage of each nutrient your soil should have. Choose a fertilizer that matches this ratio, so your trees get lots of nourishment.^{[8]
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- For instance, if your NPK recommendation is 15-5-10, you’d use a fertilizer with a 15-5-10 NPK ratio for your plant.
- Some experts recommend using a fertilizer designed for acid-loving plants.^{[9]
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  Research source} Other experts from hot, dry climates suggest using a 13-13-13 or 15-5-10 fertilizer.^{[10]
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  Research source} It really depends on where you live!

Question 3 of 6:

What fertilizer is best for potted citrus trees?

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Choose a slow-release fertilizer. Citrus trees need to be watered pretty often; unfortunately, this can wash out the nutrients quickly. To counteract this, pick a slow-release fertilizer, so your tree receives nutrients gradually.^{[11]
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Epsom salt is another good option. Citrus trees thrive in acidic soil that’s somewhere between 5.5 and 6.5 pH. Thankfully, products like Epsom salt or agricultural gypsum can keep your citrus tree healthy and well-nourished, especially if your tree’s nutrients get washed out.^{[12]
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Question 4 of 6:

What is a natural fertilizer for citrus trees?

Organic fertilizer is a possible option. Some fertilizers are labeled as “organic,” which means they’re made with natural ingredients like manure, compost, and earthworm castings.^{[13]
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Research source} Look for an organic fertilizer at your home improvement store, or any place that sells gardening supplies.

Question 5 of 6:

How much fertilizer do citrus trees need?

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Mature trees need at least 1 lb (0.45 kg) of fertilizer per year of life. For reference, a 4-year old tree needs 4 to 6 lb (1.8 to 2.7 kg) of fertilizer, a 5-year old tree needs 5 to 7 ¹⁄₂ lb (2.3 to 3.4 kg), a 6-year old tree needs 6 to 9 lb (2.7 to 4.1 kg), a 7-year old tree needs 7 to 10 ¹⁄₂ lb (3.2 to 4.8 kg), and so on. If your tree is 12 years or older, use between 12 to 18 lb (5.4 to 8.2 kg) of fertilizer.^{[14]
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- Don’t give your citrus tree all of this fertilizer at once! Spread out this total amount over the growing season.
- These measurements apply to chemical fertilizers.
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Young trees need more fertilizer than mature trees. During the first year, apply ¹⁄₂ lb (0.23 kg) of fertilizer to your tree each month between February and October. During the second year, spread 1 lb (0.45 kg) of fertilizer over your tree each month. Once the third year rolls around, spread 2 lb (0.91 kg) of fertilizer around the tree.^{[15]
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- For these particular measurements, use a fertilizer with an 8-13% nitrogen content. If your fertilizer has a 17-21% nitrogen content, divide these measurements in half.
- If you’re using a balanced fertilizer (like 13-13-13), experts recommend using at least 1 lb (0.45 kg) of fertilizer on 1-year old trees, 2 lb (0.91 kg) on 2-year old trees, and 3 lb (1.4 kg) on 3-year old trees.^{[16]
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Question 6 of 6:

How do you apply citrus fertilizer?

Apply fertilizer along the base of the tree. If you’re growing an outdoor tree, spread the fertilizer as wide as the tree’s canopy, so your plant gets plenty of nutrients.^{[17]
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Trustworthy Source
EDIS
Electronic database of the University of Florida Institute of Food and Agricultural Sciences's peer-reviewed articles
Go to source} To be safe, always double-check your fertilizer label to make sure you’re applying it correctly.^{[18]
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- Some liquid fertilizers might be sprayed on your tree’s leaves.

Expert Q&A

Question

What is the best balanced fertilizer?

Matt Bowman
Gardener & Owner, Tradition Market & Garden
Matt Bowman is a Gardener, Landscaper, the Owner of Georgia Farm to Table, and the Owner of Tradition Property Services in Atlanta, Georgia. With over 20 years experience, he specializes in organic gardening, landscape maintenance, handyman services, homecare services, and supplying Christmas trees. Matt earned a BA in Journalism from the University of Georgia.

Matt Bowman

Gardener & Owner, Tradition Market & Garden

Expert Answer

The best fertilizer for your soil depends on the balance of nutrients in the soil. Do a soil test to help you figure out your soil's needs so you can get the right fertilizer.