10 Things that You Need to Know About Potato Fertilizer


If you plan to plant potatoes, you need to be ready to use fertilizers. Fertilizers play a crucial role in the growth of your fertilizers. What are the things you need to know about potato fertilizer?

Growing potatoes needs proper soil preparation, planting time, and nutrients. You need to learn about Fertilizers and others. You were feeding Potato Plants and learning how not to over-fertilize.

Things you Need to Know about Potato Fertilizer

Potato growers apply fertilizer during the plants’ growth period (3 to 4 months). Here are some things you need to know about potato fertilizer to ensure you get a high yield from your potato plants.

1. Know the Right Nutrients of the Fertilizer

To know the fertilizer’s right nutrients, you need to look at the Nitrogen, Phosphorous, and Potassium (N-P-K) ratio of the fertilizer. The N-P-K is a representation of the chemical symbols of the nutrients.

Nitrogen (N) promotes the growth of your plant’s leaves.

Phosphorus (P) promotes the growth of your plant’s roots, flowers, and the development of fruits.

Potassium (K) is the nutrient that promotes the plant’s overall functions to allow the plant to perform correctly.

The N-P-K of the fertilizer is written in numbers that are separated by dashes and found on the name, bottle, or package of the fertilizer. The numbers refer to the nutrient content of the fertilizer in percentages.

A 10-pound bag of fertilizer labeled as 5-10-5, means it contains 5% nitrogen, 10% phosphorus, and 5% potassium by weight. The remaining 80% of the bag’s weight consists of minor nutrients.

What is the best N-P-K ratio for potato fertilizer? It should be a fertilizer with high potassium, a good amount of nitrogen, and a little less phosphorus.

Nutritious soil can have fertilizer with no nitrogen. A good quality fertilizer for your potato plant should have a higher potassium percentage than the rest.

2. Potato Fertilizers Should Contain other Nutrients

NPK nutrients are not the only ones you need to look for in fertilizers. Some fertilizer mixes also contain a lot of other nutrients that help in the growth of your potatoes.

Rich nutrients such as calcium, sulfur, magnesium, and a lot more – fertilizers with many extra nutrients help a lot in the proper growth of your potato plant.

3. Quick-Release vs Slow-Release Potato Fertilizer

Choosing to go for quick or slow-release fertilizers depends on the results you expect and your preference.

Quick-release potato fertilizers are typically available in a water-soluble form that immediately turns into nutrients once applied.

This can accelerate the improvement of your plant, especially if seedlings or tubers are not planted in desirable soil.

Slow-release and heavily concentrated fertilizers provide a consistent and steady supply of nutrients to your plants in the long haul. This is the reverse of flooding your plants with large amounts of nutrients at once which can upset your plant.

When using slow-release fertilizer, you do not need to water your potato plant to activate the fertilizer. The fertilizer will also not leach into the groundwater or nearby surface.

4. Potatoes can Benefit from Urea

Whether in organic or synthetic (manufactured) forms, urea is commonly used in potato plants because it has high nitrogen content and is cheap.

It is effective when applied through filial absorption (applying fertilizer directly to the plant’s leaves) and even during excessive rainfall.

5. Organic vs. Synthetic Fertilizers for Potatoes

Potato plants do not care whether you use organic or synthetic fertilizers. But if you want your potatoes to be free from chemicals, you can opt to use organic fertilizers (natural sources).

Organic Fertilizers

Organic fertilizers typically include such meals as bone, blood, fish, cottonseed, and alfalfa. Rock formations and corals are also good organic fertilizers because they typically contain potassium or other macronutrients.

These are slow-release fertilizers, and some of them may take a few months, although rarely, before completely being absorbed by your plants. Over-fertilizing will not damage your potato plants.

Synthetic Fertilizers

On the other hand, synthetic fertilizers are manufactured and come from chemical sources. These are quick-release fertilizers and are absorbed by your plants after being applied for a day or two.

Your potato plants quickly absorb them, especially when in liquid form.

The downside of synthetic fertilizers is that they are rich in macronutrients but often do not contain them, so your potatoes can be missing magnesium and calcium. They may also contain chlorine and other chemicals.

6. Liquid or Granule Fertilizers

Do you like to fertilize your potato plants with liquid fertilizers or granules?

Fertilizers that come in liquid form are poured over the soil. It easily breaks down and is quickly absorbed by your potato plant (quick-absorbed fertilizers).

You will need to be consistent in your fertilizing, but it helps your potato plants a lot, especially during the early growth.

Granules are pellet-like and not as fine as powder. You pour the granules and mix them with the soil to quickly break down and absorb them by your potato plants after a few weeks (slow-release fertilizers).

7. Know the Amount of Fertilizer you Need

You do not want to buy a huge bag of granules for only one or two plants. You also do not want to buy a small bag for a row of potatoes.

The amount of fertilizer you need also depends on whether your potato plants are planted in pots, garden soil, or garden beds.

A pound of granules is usually good for about two months of fertilizing if you have one or two potato plants. One potato plant would need about 30 ounces of fertilizer per season.

8. Know when to Fertilize Potato Plants

Your potato plant will generally have higher requirements for nitrogen ( for example, 34-0-0) within the first two months of its growing stage when its foliar is developing rapidly.

In the second month up until two weeks before harvest time, your potato plants will need more potassium (for example, 14-7-22) to allow your plant to grow well-shaped potatoes.

9. Fertilizing your Potato Plants

The most commonly used fertilization system includes 4 major applications. The first application is at the time of planting and the second to the fourth application is after every 20-25 days.

10. Avoid Over-Fertilizing

It is never a good idea to over-fertilize your potato plants. Over-fertilizing can stress out your potato plant resulting in over-developed or deformed potatoes.

The leaves will often be pale and not green. The leaves will also tend to roll up. Check the nutrients of your soil so you can avoid over-fertilizing and under-fertilizing your potato plant.

Additional Information

Soil Requirements

Acidic and loose soil will lead your potato tubers to have a high yield. It is, therefore, essential to test the acidity of your soil before planting your potatoes.

Your soil needs to have acidity pH levels of between 4.8 to 6.5. A higher or lower pH level than this range means you may need to adjust the soil’s acidity.

Best Time to Plant

Potatoes are cool weather vegetables, so early spring is the best time to plant them. Planting your potatoes 2 or 3 weeks before the last frost date will give you the most satisfactory yield.


Your potato plants need large amounts of nutrients to have an acceptable yield. Fertilizers can provide your potato plants with the nutrients they need for a high yield.

A balanced soil and potatoes planted at the right time will need potato fertilizer to jumpstart the successful growth of your potato plant.

Applying extra nitrogen and potassium will help your plants form new tubers to form new stems and foliage to grow potatoes.

Final Thoughts

Using the best fertilizer can maximize the yield of your potato plant. Knowing everything about potato fertilizers will allow you to choose the best fertilizer and the best way to fertilize your potato plant.

Jenny Marie
Tribal Writer

Edited By
Patricia Godwin

Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

Recent Posts