When to Fertilize Citrus Trees in California | 5 Best Tips

If you want flavorful citrus fruits, you have to fertilize your citrus tree at the right time.

As they are heavy feeders, you have to fertilize them regularly to get a good harvest.

So, when to fertilize citrus trees in California?

Here’s everything you should know.

When to Fertilize Citrus Trees in California?

How often you fertilize your citrus tree depends on different factors. For example:

• Type of citrus
• Climate
• The health of the plant

Before moving ahead, here’s something that you should know.

Citrus trees love the hot temperature of Southern California. The warmth allows the fruits to mature and sweeten.

In the case of lemons and limes (where sweetness is not a concern), the lesser warm temperature can play an important role.

When you know this, let’s dive straight into the topic.

Overview: Apply the first dose to your citrus tree in February. In Southern California, this is the time when the temperature starts to warm up. The second dose in May will help your citrus tree to nurture the fruit. During this period, nutrient uptake is high. The final application in September will prepare your citrus tree for winter.

Let me explain this in detail.

Fertilize in February:

Generally, this is a good time to apply the first dose to your citrus tree in Southern and Central California.

Here’s why.

At this time, you will mostly have spring-like days with a few warmer afternoons. As the temperature starts to warm up, the trees need energy.

After fertilizing in September of the previous year, this is the time to start the fertilizer applications again.

This early application is important due to the “Mediterranean climate” of Southern California.

This simply means that this region has a warmer average temperature than Northern California.

This will provide essential nutrients to your nutrient-hungry citrus tree.

A good start, isn’t it?

Feed Your Tree Throughout the Growing Season:

After February, there are two key times for fertilizer applications:

• May (spring)
• September

You can remember these fertilizer application dates by the following holidays: Valentine’s Day (February), Memorial Day (May), and Labor Day (September).

If I talk about sweet orange trees, such as Washington Navel and Valencia, they bloom in spring.

So, the second dose in May will help your citrus tree to nurture the fruit.

The best part?

During this period, the maximum nutrient uptake occurs.

If your citrus trees need it, you can fertilize again in September as well. Here’s why.

This final fertilizer application of the year will prepare your citrus tree for winter. At this stage, a fertilizer formulated for citrus trees is recommended.

This is because it will provide essential micronutrients. These are:

• Manganese
• Iron
• Zinc
• Copper

This takes us straight to the next topic.

Avoid Fertilizing Newly Planted Trees:

Newly planted trees have to establish roots first to absorb nutrients.

According to the University of New Hampshire, fertilizing them at this stage can inhibit their root growth.

So, you should wait until they are in the ground for at least one year.

As we discussed earlier, there are three key times for fertilizer applications. This is because fertilizing too late in the season can cause the fruit quality to decrease.

Now, I have a question for you.

Is it easier to grow trees in Southern California? Let’s find out.

Northern vs Southern California:

You should know that growing citrus trees in Northern and Southern California is a bit different.

If I talk about Southern California, it is comparatively warmer year-round.

In contrast, Northern California has colder winters and “moderately oceanic” temperatures.

This is the reason why the fertilizing timeline varies. So, here’s the takeaway.

As citrus trees love plenty of sunshine and warmth, you will find them throughout Southern California. So, it can be a better option to grow citrus.

But, some varieties will prefer the slightly colder temperature of Northern California.

Now, let me summarise this.

Citrus trees are energy-hungry. So in cooler areas, you should fertilize them every month or two during the growing season.

For the dry areas of Southern California, you can fertilize them in February, May, and September.

But, this can vary depending on the type of citrus tree and the condition of the soil.

With that being said, let’s move on to the next topic.

When to Fertilize Citrus Trees in Pots:

The idea over here is simple.

As potted citrus trees have less soil to work with, they need less fertilizer than planted citrus trees.

As the new growth begins in late winter or early spring, you should start fertilizing.

Generally, you should feed them once a month during months of active growth. At this stage, the nutrient uptake is high.

When you move on to the periods of dormant growth (winter), you should avoid fertilization.

This takes us straight to the next topic.

How To Fertilize Citrus Trees?

The application process will depend on the type of fertilizer you use.

So, let’s discuss some options in this step-by-step guide.

Step 1: Conduct a soil test

Although this is not compulsory when it comes to fertilizing citrus trees, it is recommended.

This test will allow you to make informed decisions about feeding your tree. Here’s why.

You will learn about the content of micronutrients in the soil. This is important as micronutrients such as iron, calcium, and magnesium are important to produce healthy fruit.

With this, let’s move on to the next step.

Step 2: Select a fertilizer

At this stage, you have two options:

1. Organic fertilizer
2. Inorganic fertilizer

Let me break this down for you.

Inorganic (Granular):

These (dry) fertilizers in the form of pellets work great for large or potted trees.

The question is, how to apply them to citrus trees?

Firstly, read the instructions on the package. Now, sprinkle the granules over the dripline.

When you are done, scratch these granules into the soil. Finally, water the soil.

A tip over here is to add fertilizer to damp soil (instead of dry soil). This will prevent root burn.

With this, let’s talk about the application rates.

The idea over here is simple.

For mature trees, a pound of fertilizer for every year of its age should be used.

For the first 3 years, a balanced fertilizer, such as 10-10-10 or 13-13-13, can be used.

For trees that are 4 years or older, a fertilizer with a low phosphorus content (such as 15-5-10) is preferred. You can also use a fertilizer formulated for citrus trees.

This takes us straight to the next topic.

Inorganic (Liquid):

This is the second option.

You can also use a liquid fertilizer to provide essential nutrients to your citrus tree.

They act as “quick-release” fertilizers. This is great for mature trees as they will quickly receive nitrogen and other nutrients.

If your citrus tree has yellow leaves, this quick-release formula can solve your problem.

To apply this fertilizer, dilute it with water according to the instructions on the package.

Now, slowly pour this solution directly on the soil and water simultaneously.

With this, you have given essential nutrients to your citrus tree. Amazing, isn’t it?

Now, let’s talk about some organic options.

Organic Fertilizers:

If you are considering some organic options for your citrus tree, it is a great idea.

So, let’s take a look at some of them.

• Fish emulsion fertilizer: This liquid organic fertilizer is good for citrus trees.

As it is made from the byproducts of the fishing industry, it provides nitrogen, phosphorus, and potassium.

Fish scraps, fish meals, and fish oil are some byproducts used to make fish emulsion fertilizer.

The best part?

It provides important trace elements, such as magnesium and calcium, to citrus trees as well.

As the fish emulsion fertilizer contains fish oil, it should not be sprayed during the heat of the day. So, it is better to spray it on your citrus trees early in the morning.

Over here, there’s something that you should know.

Citrus trees are heavy feeders. So, the fish fertilizer may not contain enough nutrients for your tree.

So, it is better to use it as a supplement only.

Related: Fish Emulsion Fertilizer For Roses | Good or Bad?

Seaweed Fertilizer | Is it Good For Roses?

With that being said, let’s move on to the next organic option.

• Compost: An all-purpose compost works great for most citrus trees.

As compost is made from rotted-down organic matter, it provides essential nutrients. These nutrients are required by a citrus tree to produce fruits.

Plus, it also improves the drainage of the soil.

Talking about organic fertilizers, you can also use the banana peel fertilizer as a supplement.

The high potassium content is great for flowering and fruiting. The idea is to use these organic fertilizers as a supplement.

You May Also Like:

Banana Peel Organic Fertilizer | All You Need to Know

Is Mushroom Compost Good for Tomatoes?

As discussed earlier, citrus trees are heavy feeders. To learn more about these organic options, you can refer to these detailed guides.

Related Questions about Citrus Trees:

Now, let me answer some frequently asked questions about citrus trees.

Wrapping Up:

If you want to grow a healthy citrus tree, you have to fertilize it at the right time.

To sum it up, California is a perfect place to grow citrus trees. The climate of Northern and Southern California varies slightly.

So, some citrus trees are more popular in one region. Now, let me summarise this for you.

In the hot and dry areas of Southern California, a first dose in February is recommended. This should be followed by a second fertilizer application in May.

Finally, a dose in September will prepare your citrus tree for winter.

If you have made it this far, I recommend you check out these amazing resources as well:

When to Fertilize Hydrangeas in California for Beautiful Blooms

What is the Best Time to Fertilize Mango Trees in Florida?