Best Fertilizer for Lemon Tree: Top 12 Picks & When To Apply

If your lemon tree is lacking essential nutrients, growing lemons may prove to be difficult. In order to produce a maximum of five batches of fruit per year, these trees require ample amounts of nitrogen, phosphorus, and potassium. Fortunately, the process is not overly complicated.

One of the biggest things that you’ll need to look for is acidity. Sulfer is commonly added to fertilizers to help adjust the pH to be favorable for citrus trees.

All lemon varieties and other citrus trees will do best with a soil pH of 5.5 to 6.5. This could be the main factor in your tree not thriving, so doing a soil pH test is a great idea to narrow down what is missing. 

Look for a fertilizer that has ample nitrogen but not an overly high amount.

Citrus trees will flower and fruit on the newest current year’s growth, and without ample nitrogen, they won’t be able to grow new shoots and leaves to flower and produce fruit.

However, you don’t want to forget the phosphorus and potassium! Without them, you will end up with a poor root structure and minimal to no flowers — no flowers mean no fruit! 

Trace minerals like calcium, magnesium, iron, zinc, and others are also important.

The more robust and diverse the fertilizer’s ingredients, the better chance you’ll have of giving your trees (and any nearby plantings) everything they need to produce bountiful harvests! 

Check out the great fertilizers below to help you pinpoint which is right for your needs! They come in many different forms; some are easier than others to apply, and some have better nutrients than others.

This list will help you decide, so take a look, and then get to feeding your tree!

Main Recommendations

  • Best Organic Fertilizer for Lemon Trees: Espoma Organic Citrus-tone. This organic blend comes ready to use, contains no toxic ingredients, and promotes vigorous growth and fruit production. 
  • Best Fertilizer Spikes for Lemon Trees: Jobe’s Fruit and Citrus Fertilizer Spikes. These are great for feeding your trees for months at a time and only need to be replaced twice per year. 
  • Best Liquid Fertilizer for Lemon Trees: EZ Grow Professional Liquid Tree Fertilizer. Liquid fertilizer delivers nutrients immediately to your tree, so it is best used when a tree is seriously suffering to give it a quick boost. 
  • Best Value Fertilizer for Lemon Trees: Making your own can save money, but you’ll need to gather the ingredients yourself. If you want value without the hassle, check out Down To Earth Citrus Fertilizer.
  • Best Fertilizer for Potted Lemon Trees: Jobe’s Fertilizer Spikes for Potted Trees. Liquid and granulated fertilizers can wash out of the bottom due to overwatering and fast-draining soil. These spikes will slowly release nutrients without the worry that the fertilizer will be gone quickly. 

When To Fertilize Lemon Trees

It can be difficult to pinpoint when to fertilize a lemon tree because most of the time it will have fruit ripening while beginning to flower again.

Try to fertilize the tree when there are more flowers than fruit present. If you fertilize when there is still fruit present, it may make the fruit taste watered down, and they will take longer to ripen. 

A mature lemon tree loaded with fruits.

1. Down to Earth Organic Citrus Fertilizer

With an NPK ratio of 6-3-3, this mix provides ample nitrogen while supplying a sufficient amount of phosphorus and potassium.

I recommend this fertilizer the most because it has ingredients available right away and also slow-release components. 

2. Dr. Earth Natural Wonder Organic Fruit Tree Fertilizer

Its NPK of 5-2-2 is great for providing a little bit of all the essentials. It also comes with Dr. EarthTruBio, which provides beneficial microbes to the soil for optimum absorption and soil health. 

3. Espoma Organic Citrus-tone

Espoma is a trusted brand that offers this organic fertilizer that’s great for all citrus and avocado trees.

With an NPK of 5-2-6, this formula is helpful for root and flower development. It also comes with trace amounts of calcium and magnesium, which are helpful in budding and fruit development. 

4. Jack’s Classic Citrus Food

This is a nutrient-heavy fertilizer with an NPK of 20-10-20! It is best used with a tree that needs a big boost of nutrients to get it back on track.

It also has a mix of micronutrients to help fill any other gaps in the soil biome. 

5. Miracle-Gro Shake ‘n Feed Citrus, Avocado, Mango Plant Food

This is one of the easiest and most versatile fertilizers on this list. All you need to do is apply every 3 months.

With an NPK of 8-2-10, it is focused on strong root growth and flower production. Simply shake and feed! 

6. Jobe’s Fruit and Citrus Fertilizer Spikes

Fertilizer spikes are great for their slow-release ability. Insert them equally spaced around the tree, depending on the size of the tree and the package’s instructions.

With an NPK of 9-12-12, you’ll want to use it when the soil is less than favorable to help the roots develop strong growth. 

7. Jobe’s Fruit and Citrus Fertilizer Spikes for Potted Trees

Similar to the full-size spikes, these are much smaller for potted uses. They have an NPK of 3-5-5, so they feed gently but still slow-release the nutrients into the soil. They should be replaced every 8 weeks. 

8. Miracle-Gro Fruit & Citrus Plant Food Spikes

Requiring only two applications per year, these are easy to use and can feed for 6 months at a time.

Be sure to rotate where you add the stakes in the ground to ensure that you’re feeding all the roots around the tree evenly. 

9. EZ-gro Professional Liquid Citrus Tree Fertilizer

For trees that need that a boost fast, try a liquid fertilizer. With an NPK of 20-3-19, you’ll give your tree ample nutrients to thrive!

Focused on vegetative growth and root development, it should help both above-ground and below-ground growth evenly. 

10. FoxFarm Happy Frog Organic Citrus and Avocado Fertilizer

An organic option, this 7-3-3- fertilizer is filled with trace minerals that help to provide filler for all the small nutrient deficiencies.

It also has bountiful soil microbes to help nourish the soil and promote a healthy soil biome. 

11. Fertilome Fruit, Citrus and Pecan Tree Food

This fertilizer stands out because it has an NPK of 19-10-5, the highest phosphorus content of the fertilizers on this list.

Phophosoruos is great for the transport of nutrients through the tree and can help facilitate uptake through the roots and the entire vascular system. 

12. EarthPods Fruit & Citrus Plant Food

A different type of fertilizer that comes in capsule form, these are shaped like a large medicine pill.

They aren’t very effective when fertilizing large trees, but potted trees can benefit greatly from these with their complete nutrient coverage.

Lemon Tree Fertilizer Homemade

If you want to make your own fertilizer rather than purchase a premade mix, you can!

However, measuring the fertilizer in terms of NPK value can be difficult when making your own, so use percentages or ratios in your mixture. 

The best ingredients to use in a homemade mix are grass clippings, leaf litter, banana peels, eggshells, coffee grounds, and raw ingredients like sulfur, bonemeal, and kelp meal.

Use a ratio of 65-75% nitrogen materials to 25-35% potassium and phosphorus ingredients. 

Nitrogen ingredients include grass and leaves. Phosphorous and potassium materials include banana peels, eggshells, coffee grounds, sulfur, bone meal, and kelp meal.

You can purchase raw ingredients and mix your ratio well if you understand the exact deficiency your tree has. 

Final Thoughts 

Lemon trees need supplemental nutrients if you want to get the most out of them and enough fresh lemonade all summer long!

Whether you choose to use a granulated version, fertilizer spikes, or liquid, you’ll see a boost in your tree’s vitality and fruit production over the coming months.