6 Best Fertilizers for Avocado Trees | How and When to Use

As far as fruit trees go, avocados are pretty special. They love loads of sunshine, well-drained, acidic soil (with a pH range of 6 – 6.5), and just the right amount of moisture.

In order to thrive, they need fertile soil, together with a boost of the three primary macronutrients to really bring out the best possible yield of delicious nutrient-dense fruits.

Here you’ll find my top pick of the best fertilizers for Avocado trees. I’ll also be sharing some key pointers and my top tips about the fertilizing process.

All so you can provide these marvels of nature the care they deserve so they can reward you with tasty, buttery fruit.

Best Avocado Tree Fertilizers

If you’re curious to know which of these products are top of the pile, you’ll find an overview of them right here. But for details of how, when, and what fertilizer to use, keep reading.

Down to Earth Organic Citrus Fertilizer Mix 6-3-3

Best Organic Fertilizer

Down to Earth Organic Citrus Fertilizer Mix 6-3-3

OMRI-certified and suitable for use throughout the growing season. Loaded with all-natural ingredients including zinc to support lush foliage, robust growth, disease resistance, and better quality fruit production.

Jobe's Fruit & Citrus Fertilizer Spikes 4-6-6

Best Fertilizer Spikes

Jobe’s Fruit & Citrus Fertilizer Spikes 4-6-6

OMRI-certified and suitable for use throughout the growing season. Loaded with all-natural ingredients including zinc to support lush foliage, robust growth, disease resistance, and better quality fruit production.

Jobe’s Organics Fruit & Citrus Granular Fertilizer 3-5-5

Best Fertilizer Granules

Jobe’s Organics Fruit & Citrus Granular Fertilizer 3-5-5

Slow-release organic granules, ideal for use from bud set onwards or where the soil is already nitrogen-rich. Suitable for ground-planted citrus and other fruiting trees as well as avocados. 

Choosing the Best Fertilizer for Avocado Trees

If you love blooms, lush foliage, and rich pickings come harvest time, you will understand the importance of getting it right on all fronts where tree care is concerned. And selecting the appropriate fertilizer for your precious trees is right up there on that list of important factors.

Here’s a rundown of what you will need to be aware of when choosing a product that is right for your Avocado trees.

Avocado Tree Fertilizer N-P-K Ratio

These three letters represent the key nutrients your plant needs to live a healthy productive life and most manufacturers present them in the form of numbers to show the proportion of each of them.

These minerals in question include:

  • Nitrogen: Essential for photosynthesis and enzyme production, this nutrient is considered the most important for your avocado’s needs since it will enable it to develop beautiful foliage.
  • Phosphorus: This nutrient holds the key to your avocado producing delightful fruit. It is also important for your tree’s root system which is essential to its health.
  • Potassium: This mineral will keep your avocado looking bright and perky, thanks to its role in overseeing water regulation; it also helps protect plants against drought and cold temperatures and the fight against pests and diseases.

Selecting a product with the right amount of nutrients can make all the difference between a robust, flourishing plant capable of providing delectable green fruit, and one which unfurls verdant foliage only to fall short where it really counts — providing velvety creamy avocados.

That means selecting a fertilizer with a 2-1-1 ratio to provide it with healthy greenery — all the better for the production of the energy required to keep the plant in excellent health, enabling it to produce high-quality fruit.

It is also possible to select a balanced fertilizer i.e., a product that contains all three key nutrients in equal proportion. Fertilizers in this category are recommended for citrus trees but can also work wonderfully for your plant as well.

Zinc 

The fertilizer you select for your avocado should also ideally contain zinc. The mineral is responsible for enzyme production as well as the synthesis of carbohydrates and proteins; these factors will ultimately affect the quality of the fruit your tree will be able to produce. Plants affected by a deficiency in zinc tend to produce smaller rounded fruit, rather than the large pear-shaped offerings provided by their healthier counterparts.

Avocado Soil pH and Nutrient Uptake

The acidity or alkalinity of the soil you choose will affect your avocado’s ability to absorb nutrients from it.

Like most fruit-bearing trees, avocados prefer acidic soil. While a pH of 6 – 6.5 is recommended, most can thrive with a pH of 5 – 7.

Alkaline soils can affect their ability to absorb zinc and iron. The latter nutrient plays a key role in the production of chlorophyll, the green pigment which absorbs the sunlight used in photosynthesis and glucose production. 

Carrying out a soil test before planting is highly recommended. If your soil’s pH is too high, you will need to lower it using acidifying nitrogen, elemental sulfur, organic mulches, or sphagnum peat, for example.

To ensure you carry out the procedure correctly, you could visit your local extension office for some advice which will come in handy.

Granular Vs Liquid Fertilizer

Two of the most common kinds of fertilizers, each offer its own unique set of perks and drawbacks in terms of application, storage, cost, and the rate at which they deliver nutrients. They are explored in further detail in the following sections.

Liquid Concentrate or Spray

Easy to mix, they come with the promise of nutrient consistency. Liquid fertilizers are also especially versatile and can be applied to the leaves of plants to provide them with a fast-acting dose of nourishment. 

Data published by the University of California recommends using zinc-based liquid fertilizers as a foliar spray to encourage better absorption of this important mineral by avocado trees.

That said, they can be more expensive compared to granular fertilizers, and may not keep as well over time.

Fertilizer Granules

Granules are often a more cost-effective option compared to their liquid counterparts.

They are easy to store, often have a long shelf life, and work by releasing nutrients over time (up to nine months in some instances). Avocado trees respond well to slow-release fertilizers especially those with a higher ratio of nitrogen. Fast-acting feeds can sometimes burn their surface feeder roots if absorbed too quickly.

Spread them by hand or with a broadcast spreader tool for wider, larger applications. Typically, granules need to be watered in once applied in order to become activated.

Fertilizer Spikes

Considered to be even more convenient compared to granular fertilizers, spikes also release their goodness slowly and can be an excellent option for young trees over a year old. This gradual release of nutrients means that you will only need to worry about issuing nutrients about twice a year: in spring and autumn.

Spikes offer an odor and fuss-free option when it comes to fertilizing however, they can shatter when applied and so care should be taken to prepare a hole for inserting them in or ensuring the soil is sufficiently soft before punching them in.

Cost can also be a possible drawback with spikes since they are usually the most expensive option of all with more spikes being required for larger trees and plants.

Organic vs Synthetic Fertilizers

Organic fertilizers are made up of natural ingredients such as earthworm castings, fishmeal, guano, sandstone, seaweed, etc.

They do not present the risk of an excessively high concentration of nutrients so there is less chance of fertilizer burn, and they can improve moisture retention in the soil while also adding structure to it.

However, they can be a costlier option compared to their manufactured counterparts.

Synthetic fertilizers on the other hand are produced as the result of a manufacturing process. They usually contain nutrients in a higher concentration compared to organic fertilizers and are often cheaper.

The main disadvantage of synthetic fertilizers is that they are not used correctly. They can pose a potential threat to the environment if allowed to run off into waterways and they can harm animals and people if ingested.  

Best Avocado Tree Fertilizer Reviews

My search for the best fertilizers for avocado trees has taken me far and wide with my primary considerations focusing on quality, nutrient ratio, value for money, performance, and ease of use. Here’s what I’ve found.

Pros

  • Contains zinc which is essential for avocado fruit production
  • Suitable for use from young trees up to maturity
  • Gentle enough for respect applications throughout the growing season

Cons

  • The odor may be unpleasant

This organic granular fertilizer from Down to Earth contains a unique blend of ingredients including kelp and fishbone meal to support your Avocado trees with robust growth and disease resistance throughout the growing season. 

The mix also includes langbeinite which is a natural form of potassium to support bud development and zinc for fruit size and quantity as well as sulfur, to support photosynthesis.

This premium brand is also listed by the Organic Materials Review Institute making it ideal if you intend to have avocados that don’t just look and taste great but are also organic as well.

The first time I came across this product, I was admittedly drawn to its ‘perfect’ ratio for my Avocado trees, knowing that I’d be able to feed them slow and steady for the duration of the growing season, but it was its final results that won me over.

I ended up with loads of rich and velvety fruits, and happy neighbors and colleagues who got to share in the bounty too. I’ve also tried them as a citrus tree fertilizer to great effect too.

How to Use

Apply 1 cup per 1 inch of your tree’s diameter moving outwards from the base of the tree to its drip line. Water properly once the product has been mixed into the soil

If your avocado happens to be an indoor plant you will need ½ cup per cubic foot of soil and once it’s all grown up, you’ll need to provide 2 – 4 tablespoons per gallon of soil, 4 – 6 times per year.

When transplanting a new avocado, mix 1 cup with the soil and place with the tree into the cavity and water.

Pros

  • Ideal for growing organic potted produce
  • Capable of improving soil quality
  • Convenient and fuss-free plant care

Cons

  • Insert with care to avoid damaging surface feeding root structure

If you want to find out what your potted avocado will look like with the very best care, then this product certainly deserves a closer peek. 

These slow-release spikes from Jobe’s come with mycorrhizal fungi that enhance your plant’s root system and enable it to take in more phosphorus so you can be sure that potting compost remains nutrient-rich for longer.

They also contain archaea which means that nutrients are readily available to your plant while also breaking down any harmful substances in the soil.

I use these when I know the soil in which my avocado trees are planted is fresh and nutrient-rich and there’s no need to add too much additional nitrogen.

These are great for fertilizing other indoor fruit tree varieties and I’ve used them with great success when my peach tree needed help to blossom. The outcome was a flurry of beautifully sweet and fragrant fruit. 

How to Use

Insert two spikes per 6-inch diameter of your plant. (However, 6 spikes should be inserted for a 30-inch diameter). More can be applied after 6 weeks for the remainder of the growing season.

Pros

  • Ideal for nitrogen-enriched soil
  • Will not contribute to runoff
  • Contains archaea to break down compounds and improve soil quality

Cons

  • The odor may be unpleasant

Some of my favorite products are those capable of working wonders for my plants no matter what developmental stage they are at and these slow-release granules from Jobe’s Organics will give your plant a head start even before you plant it and then onwards, throughout its growth cycle. 

I use this feed for ground-planted avocado trees where I know that the soil is already nutrient-rich and where I’ve mulched well over winter. 

The added phosphorous and potassium means it has been specially manufactured to enable plants to fruit prolifically and to protect them against pests and diseases and potential summer drought too.

How to use

For shoots mix 1½ tablespoons (for every 2 inches of height or for a 4-inch pot)  or 1½ cups per 10 inches (of soil)  or for a 16-inch pot.

Switch things up for larger plants that need more food with 1½ cups per foot of spread — increase to 2 cups for 3 feet or more.

For your grown avocado tree, apply 3 cups per inch of trunk diameter.

Pros

  • Capable of improving fruit yields and ensuring lush verdant foliage
  • Ideal for a wide range of shrubs and fruit trees

Cons

  • Spikes may be fragile

As a gardener, I love the convenience and whenever I am in search of the perfect nutrient balance for avocado trees and a rather hands-off approach, this is what I reach for.

Manufactured specifically for your avocado tree, it is just what it needs to be able to effectively handle the demands of spring and fall. And like the very best products you’ll be able to use it for your other fruit trees too.

How to use

The soil must be moist before driving spikes into it. Place a cap on each spike before hammering it in at the drip line of the tree. Once in, remove caps and preserve them for future use.  The spikes should be driven 2 inches below ground level and be at least 3 feet apart.

Pros

  • Contains essential micronutrients
  • Reduces the risk of nutrient burn
  • Ideal for a wide range of shrubs and fruit trees

Cons

  • Read the label to avoid over-fertilizing

Striking the right balance between providing the appropriate amounts of nutrients for your avocado and avoiding the dangers of overfeeding can be pretty challenging.

But with Miracle-Gro Citrus, Avocado, & Mango Food which provides slow-release nitrogen and helps to encourage a higher yield, you will be able to give your avocado a healthy helping of nutrients while also reducing the risk of burning.

The fertilizer also contains iron, manganese, and magnesium and will ensure healthy foliage, robust growth, and efficient use of nutrients right through the growing season.

Once you have applied it, you will be able to focus on other gardening tasks for 6 weeks until feeding time comes around again.

How to use

Apply to 1 – 3 inches of the soil or mulch and water.

Reapply following six weeks.

How to Fertilize Avocado Trees

Knowing how and when to fertilize your avocado tree is just as important as obtaining the right product. 

That means being aware of just how much your plant needs at set seasons and stages in its life cycle to cultivate a healthy plant that will beautify its surroundings and fruit prolifically for longer.

Avoiding Avocado Tree Fertilizer Burn

Fertilizer burn occurs when salts from a fertilizer become especially concentrated and allowed to build up in the soil. Avocado trees are particularly susceptible to this scorching of roots or leaves when fertilized with too much product, too often or when nitrogen ratios are excessive.

A build-up of fertilizer salt draws moisture out of the soil which means there is less water for roots to absorb. When fertilizer burn occurs, the leaves of your avocado tree will start to brown at the tips.

You can prevent your avocado tree from experiencing fertilizer burn by:

  • Following the manufacturer’s instructions for measuring and administering fertilizer
  • Irrigating your plant thoroughly following the application of granular fertilizer
  • Using organic fertilizers which come with a reduced risk of fertilizer burn

When to Fertilize Avocado Trees

Avocados should be fertilized first in spring with a fertilizer that contains a higher ratio of nitrogen such as the Down to Earth or Miracle-Gro products that I have featured in my review. This will get foliage growth and root development well underway as the growing season kicks off.

Feed again at bud set, this time with a feed that contains a higher proportion of phosphorous and potassium as this will encourage bud, flower, and fruit development, protect against pests and diseases and help to regulate water intake through any periods of summer drought.

Fertilize once more in the fall as this last application will ensure that any depleted nutrients are replenished, and your avocado trees will have the sustenance they need and protection against cooler weather during the coldest months of the year. 

Avoid fertilizing during the winter months as this may bring them out of dormancy. I do recommend, however, mulching over winter. This will not only increase soil nutrients but also provide roots with a layer of insulation against frost.

Fertilizing Avocado Trees Pre-Fruiting

Ensuring your avocado tree is well equipped for key moments of its lifecycle will enable it to emerge healthy and robust rather than stressed and weakened.

I recommend using a fertilizer with a higher ratio of phosphorus and potassium immediately before the budget. This will not only increase the potential for an abundant harvest, it will also increase the size of fruit and protect against a potential invasion of pests and disease.

How Often to Fertilize Avocado Trees

Avocado trees need to be fertilized a minimum of three times a year and only during their growing season. Once in spring, once in summer, and then in the fall.

The nutritional needs of the plant will depend on its age and soil conditions and special care should be taken to avoid administering excessive quantities of fertilizer to your avocado.

I advise conducting regular soil tests to understand any nutrient deficiencies in your soil, paying particular attention to nitrogen levels. As avocado trees mature, they benefit from more nitrogen when compared to younger trees.

Verdict: Best Fertilizers for Avocado Tree

It is not often possible to find a product that ticks every box. However, the Down to Earth Organic Citrus Fertilizer Mix 6-3-3 comes pretty close and is the perfect choice for nitrogen-loving Avocado trees. Its natural ingredients which have been proven to boost growth are just what every fan of gardening needs to enjoy miraculous results and exhilarating rewards after months and even years of meticulous care.

Down to Earth Organic Citrus Fertilizer Mix 6-3-3

Best Organic Fertilizer

Down to Earth Organic Citrus Fertilizer Mix 6-3-3

OMRI-certified and suitable for use throughout the growing season. Loaded with all-natural ingredients including zinc to support lush foliage, robust growth, disease resistance, and better quality fruit production.

For potted varieties and if convenience is what you are looking for then I recommend you choose Jobe’s Fruit & Citrus Fertilizer Spikes. These are odor-free and slow-release, meaning there is more time for enjoying and less time for tending.

Jobe's Fruit & Citrus Fertilizer Spikes 4-6-6

Best Fertilizer Spikes

Jobe’s Fruit & Citrus Fertilizer Spikes 4-6-6

OMRI-certified and suitable for use throughout the growing season. Loaded with all-natural ingredients including zinc to support lush foliage, robust growth, disease resistance, and better quality fruit production.

For a granular alternative, then I suggest you buy Jobe’s Organics Fruit & Citrus Granular Fertilizer. With its 3-5-5 NPK, this is a great choice of fertilizer for bud set onwards, especially if soil conditions are already nutrient-rich and loaded with nitrogen.

Jobe’s Organics Fruit & Citrus Granular Fertilizer 3-5-5

Best Fertilizer Granules

Jobe’s Organics Fruit & Citrus Granular Fertilizer 3-5-5

Slow-release organic granules, ideal for use from bud set onwards or where the soil is already nitrogen-rich. Suitable for ground-planted citrus and other fruiting trees as well as avocados. 

FAQ’s Fertilizing Avocado Trees 

Here’s a look at what other Avocado growers are asking about meeting fertilizing needs for these wonderfully rewarding trees.