My parents have an orange tree and the last growing season didn’t provide as many fruits as the previous. While this is normal behavior for some citrus trees, they wanted to know what the best orange tree fertilizers were. So, I put together this list along with a description of the products.
The best orange tree fertilizer you can buy is one that has an NPK ratio of 2:1:1 (such as a 6-3-3). Additionally, orange tree fertilizers should have a slightly acidic pH of 5.5-6.5. Last, check for reputable brands that have organic, slow-releasing, and quality nutrients. These can be found at your local nursery.
In the rest of this article, we’ll review what should be in orange tree fertilizer, the top three fertilizers, and other common questions when using fertilizer for your orange tree. Let’s jump in.
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What Should You Look For in Orange Tree Fertilizer?
There are a lot of orange and citrus tree fertilizers out there, so it can be hard to sort through the noise. To help with this, here are 5 points you can look for to better your chances of finding a nutritious orange tree fertilizer.
- Quality ingredients
- Well-known brand
- NPK ratio of 2:2:1 (for example, an NPK of 6-3-3)
When looking at large brand fertilizers, many have synthetic nutrients that aren’t able to be absorbed as well as naturally occurring nutrients. This is why looking for fertilizer brands that have organic and high-quality ingredients is key.
Almost all synthetic orange tree fertilizers will have additives or a process that improves the shelf-life, which means that the quality suffers.
Like human nutrition, the more alive the food is the better (this is why fresh fruit and vegetables are more nutritious and taste better).
So, if you have the choice of applying a synthetic fertilizer or a heap of fresh compost (or vermicompost in my case), it’s clearly better to go with the fresher option. This is also true when comparing store-bought fertilizers.
If you are applying compost, keep in mind it can be slightly alkaline (and orange trees prefer an acidic pH), so you can add peat moss, sand, or coffee grounds to increase the compost’s acidity.
The Top 3 Store-Bought Orange Tree Fertilizers
1. Down to Earth Organic Citrus Fertilizer Mix
Down to Earth is my first choice when it comes to orange tree fertilizers because of their reputable brand, great NPK, and their quality ingredients. If you’re interested in hearing more about the company, I wrote more on my recommended citrus fertilizer page.
Down to Earth’s Citrus Mix has a 6-3-3 NPK (nitrogen, phosphorus, and potassium-the three main ingredients for plants). This fertilizer has all the nutrients your orange tree needs for both foliage or fruit growth. Additionally, it works for both planted and potted orange trees.
This citrus mix also includes secondary plant nutrients such as calcium, sulfur, iron, zinc, and other micronutrients.
Even though I personally like to make my own citrus fertilizer, Down to Earth is my go-to when it comes to store-bought citrus tree fertilizers.
To see more about Down to Earth, you can check it out here on Amazon.
2. Jobe’s Organics Fruit & Citrus Fertilizer Spikes
Jobe’s is also a reputable brand, and their measured citrus fertilizer spikes make it super easy to apply fertilizer. As I mentioned, I prefer making a homemade orange tree fertilizer, but I recommend Jobe’s for any citrus tree beginner, as they make applying fertilizer incredibly easy.
Jobe’s citrus spikes have an NPK of 3-5-5, which is a little lower nitrogen content than I would like to see but is still beneficial for most citrus trees.
This NPK and citrus mix is best suited for mature citrus trees that are focusing less on growing foliage and more on growing fruit.
Nitrogen is the primary nutrient to grow branches, leaves, and roots.
Here’s their recommended number of spikes for the size of your potted orange tree.
|Pot Diameter||# of Spikes|
The only thing that I would caution against is to make sure the fertilizer spike is hidden well. Since it can’t be scattered in the soil like powdered or granulated fertilizer, children or dogs can find the spikes and try to eat them.
Keep them out of reach if possible, and well-concealed (our dogs love fertilizer and will sniff it out and dig it up quickly). The best way is to cover the fertilizer with several inches of soil (still careful not to damage the shallow orange tree roots) and provide a generous watering session.
Overall, Jobe’s is a great fertilizer for those new to fertilizing orange trees. You can check out Jobe’s citrus spikes here on Amazon.
3. Espoma Citrus-Tone Plant Food
While I haven’t used Espoma’s citrus tree fertilizer yet, I have used their organic potting soil, and I’m a big fan of it. I use it for my potted herbs, microgreens, and vermicomposting bin. After doing some research on their citrus fertilizer, I can confidently say that it’s just as high-quality as their potting soil.
Espoma’s citrus fertilizer has an NPK of 5-2-6. Even though this mix is higher in potassium, it’s still great for citrus trees. Potassium helps citrus trees with their overall health as well as water retention, so having a bit extra won’t hurt.
How Often Should You Apply Fertilizer?
Orange trees should be fertilized at least once a year, or every growing season (this is typically in the spring). However, some fertilizers are fast-releasing and require more frequent feedings. This is why it’s a good idea to reference the instructions on the fertilizer’s label.
Normally, most quality orange tree fertilizers are slow-releasing and are potent enough to apply once a year. There might be some shady brands out there that suggest more frequent feeding, but this can be to simply buy more of their product.
Because of this, the best two tasks to do when looking at how often to apply fertilizer is:
- Start small with your fertilizer application and see how your orange tree reacts
- Purchase a high-quality fertilizer as this means more nutrients get absorbed by the tree and not washed away in the soil
How To Fertilize Orange Trees
Fertilizing Planted Orange Trees
To fertilize planted orange trees, follow the amount suggested on the product’s package and scatter the fertilizer under the tree. Make sure that the fertilizer is under the drip line (canopy) of the tree and does not touch the tree directly as this can chemically burn it. Cover the fertilizer with 1-2 inches of soil.
It’s important to deeply water both young trees and mature trees to protect the roots from getting overexposed from the potent nutrients.
Fertilizing Potted Orange Trees
To fertilize potted orange trees, you can generally add one tablespoon for every four inches of the container’s diameter. However, this depends on the fertilizer’s potency, so check the instructions on the package. Bury the fertilizer under 1-2 inches of soil and keep it away from children and pets.
How Can You Tell if Your Orange Tree Needs Fertilizer?
The main signals of poor nutrition in orange trees include:
- Yellow leaves
- Leaves falling
- Little to no fruiting
- Excess fruit dropping
- The tree is starting to die
The most common signs of a lack of nutrition in an orange tree are if their leaves are turning yellow or falling off.
Yellow leaves can also be a symptom of overwatering, but if you check the first 2-4 inches of soil, and it feels moist (and not sopping wet), then you’re likely watering it properly. In this case, you can use the process of elimination and most likely confirm the yellow leaves are from a lack of nutrition.
More Tips To Improve Nutrition for Orange Trees
- Compost: Compost is one of the best fertilizers you can use, and often times you don’t need anything else. Aim to add 1-2 inches on top of the soil every growing season. Even though compost is a bit alkaline for citrus trees, adding onion, citrus fruits, or coffee grounds can help balance the acidity. Last, avoid touching the tree directly with compost (but still keep it under the canopy’s drip line).
- Mulching: Adding a 1-2 inch layer of mulch, such as grass clippings, bark, or leaves will not only provide a slow breakdown of nutrients for your orange tree, but will also protect the soil from drying in the sun. This also dramatically improves water retention, which means you can water less (and sometimes stop watering completely!). Like compost, avoid having the mulch touch the tree.
- Try not to disturb soil: We’re learning that soil is actually a living thing. In fact, it’s scarily similar to our gut’s bacteria, in that they process and transport nutrients. Because of this, tilling and digging are some of the worst things for soil.
- Don’t spray the leaves with fertilizer: Some fertilizers advertise to also fertilize the leaves of trees, but this actually does more harm than good. The tree’s roots evolved to access nutrients from the soil, while leaves use photosynthesis to create energy and sugars. So, when the leaves are covered in fertilizer, they’re blocked from absorbing sunlight and can even get chemically burned. Let’s leave the leaves to do their job and the roots to do theirs. Fertilize the soil and not the foliage.
- Pruning: Orange trees can benefit from pruning, but the specific type of pruning depends on the age of your tree. Young orange trees that still need to grow can benefit from pruning the flowers and fruit as this signals to the tree to continue focusing on foliage growth. On the other hand, mature citrus trees that aren’t growing anymore can benefit from pruning excess branches and foliage to redirect more energy for flowering and fruiting.
So, while it’s hard to go wrong with store-bought orange tree fertilizers, I prefer a homemade citrus fertilizer. My parents like convenience, so they ended up going with Down to Earth for the above reasons, and also because their local nursery carries it.
Whichever fertilizer you get, know that just like human nutrition, orange trees also benefit from higher quality ingredients. This also means you get more bang-for-your-buck as your orange tree can absorb more nutrients (instead of most of the fertilizer getting washed away from watering and rain).
Look for an orange tree fertilizer that’s organic, high-quality, slow-release, and has an NPK that has twice the nitrogen to phosphorus and potassium, and your orange tree will continue to thrive and fruit year after year.