9 Best Fertilizer For Potatoes + How To Use Them

We all recognize the potato as a familiar mainstay of modern cuisine. Yet, it has quite an illustrious past, dating back as far as 8000 BC. The Incas were the first to recognize this self-multiplying tuber as a rich source of calories, quickly adding it to their largely vegetarian diet.

In the 16th century, Spanish invaders added this new staple to their bounty. Upon return, cultivation spread throughout Europe. Allowing struggling countries to feed their rapidly growing populations and thus evolve into global powers. 

Centuries later, the humble spud has taken an honorable position in the top five vital crops. It’s also become the anchor of many a home garden and vegetable allotment. How to successfully grow these is not as complicated as you might think. It just takes a little patience, the right soil, and the best fertilizer for potatoes.

Choosing The Best Fertilizer for Potatoes

Just like all other edible plants, potato crops need a healthy environment in which to thrive and will always benefit from boosts of nourishment throughout the growing season to encourage healthy growth and a bountiful harvest. Potato fertilizers can provide the nutrients needed to do just that but bear in mind, you must have the right balance of acidity in your soil too.

Potato tubers grown in loose, acidic soil will undoubtedly lead to a high yield. If you are unsure of the levels of acidity in your soil, I recommend testing these levels before you begin planting. You are looking for soil acidity pH levels ranging between 4.8 to 6.5. Anything outside of this range means your soil will need to be adjusted.

Thankfully, the potato fertilizer market offers a range of solutions that will meet your needs. Plus I have listed below some ideas for naturally supplementing your soil with various composting solutions that can help to adjust your soil type.

Once your soil is balanced accordingly and your potatoes are planted, you’ll need extra potassium and nitrogen to kickstart them on the road to success. Continued applications will help to form new tubers from which stems, foliage, and new potatoes will grow.

Potato Fertilizer N-P-K Ratio

For a hardy crop, you want a fertilizer NPK of around 2-2-3 (2% Nitrogen – 2% Phosphorus – 3% Potassium). You’ll also need the means to balance out your soil’s acidity.  Adding compost to your beds will really help to introduce additional nutrients that your potatoes crop will love. Plus, I have a few tricks up my sleeve to introduce some specific nutrients that target and boost individual stages of growth. Read on to find out more.

Here’s a brief look at those specific macronutrients that really encourage your potato crop along throughout the growing process.

Nitrogen

Nitrogen is fundamental to all plants. Potatoes, in particular, use nitrogen to fuel photosynthesis. This, of course, is the process by which plants convert solar energy into carbohydrates. Potato plants require high amounts of nitrogen to produce a large and nutritious yield. But, adding nitrogen must be carefully timed with specific stages of their development.

Phosphorus             

Once tubers begin to multiply, they’re all very responsive to a healthy dose of phosphorus. This encourages more offshoots, especially when grown in poor soil. Because tubers grow beneath the soil, making it difficult for us to see when this occurs, it’s best to work phosphorus to the soil at the time of planting. 

Potassium

Potassium is vital for a high yield. This macronutrient determines the effective transport of other essential nutrients and carbohydrates from the leaves to the tubers. Potassium also decreases the occurrence of internal blackening during development.

Beyond the garden, the benefits of potassium include an extended shelf-life and richer color and flavor when cooked.

Soil pH For Potatoes

Potatoes grow in a variety of different environments that have equally varying soil types. From sandy to clay loam to well-structured soil that allows for proper root aeration and tuber development. One important aspect of healthy soil is its pH level.

Potatoes successfully grow in soil with a pH range of 5.5 – 7.0 and some fertilizers will help support this. Anything outside of this range will have a visible impact on the vitality of your plants. Too high and the metabolism of nutrients is cut off, no matter how much you apply. Too low and your crops may suffer from heavy metal ion toxicity.

Types of Potato Fertilizer

In my pick of the best fertilizer for potatoes, you’ll notice that I have focused my choices exclusively on natural and organic fertilizers. The reason for this is simple, edibles such as potato crops respond really well to soil environments that have been nourished with organic matter. But, aside from what’s good for our plants, who wants to douse the fruits of our labor in anything other than all-natural ingredients. If we are going to eat our crops then surely a non-synthetic fertilizer option is best.

For the most part, these organic fertilizers come in three main varieties:

Slow-Release vs Quick-Release Fertilizer For Potatoes

Choosing a slow or quick-release option simply depends on your preference and result expectations. Quick-release options typically come in a water-soluble form that conveys nutrients immediately upon application. Which can result in accelerated improvement, especially if tubers or seedlings are in less-than-desirable soil.

Heavily concentrated, slow-release options offer a steady, consistent stream of nutrients to plants over an extended period of time. Rather than inundating your plants with high doses of nutrients all at once, which could have a devastating effect. No watering is needed to activate and is less likely to leach into nearby surface or groundwater.

Organic Fertilizer For Potatoes 

Organic gardening means providing all the essential macro and micronutrients required by plants to produce robust tuber/root formation and crop growth. This is accomplished by manually providing plants with the same organic material as provided in nature. When mixed with handmade compost, elements like cottonseed meal and bone meal introduce vital macronutrients while also increasing the soil’s acidity.

These additives are especially beneficial in soil where the pH is too high. Increasing your soil’s acidity lowers its pH level. Below, you’ll find several options that provide these organic elements all in one product.

Urea Fertilizer For Potatoes

Urea is a common source of nitrogen found in many fertilizer formulas. But, what is urea and how does it benefit your potatoes? Natural urea is a metabolic waste byproduct of animals and is thus considered an organic form of fertilizer. However, there are also synthetically manufactured forms that are not categorized as organic.

Either way, urea has become commonplace in potato farming for its heavy nitrogen content, relatively low cost, and continued effectiveness in the event of unexpected, excessive rainfall.  It’s also really effective through foliar absorption, making it easy to apply when plants grow too large for direct soil feeding.


Best Fertilizer For Potatoes Reviews

Through personal insight, research, and knowledge plus a wealth of potato growing expertise from some experienced horticulturalists, I’ve dug deep to pull together my recommendations for the best fertilizer for potatoes on the market.

I’ve taken the liberty of delving into the world of potato fertilizing in order to root out my list of picks for the 10 best fertilizers for a bountiful potato harvest to enable you to make the right choice for your spuds and give your crop the boost they need in no time at all.

The criteria is based on what I believe to be the best potato fertilizers based on overall performance and results, ease of use, as well as taking into account customer reviews from the major retail platforms and forums.


1. Espoma Garden-Tone Natural & Organic Fertilizer | 3-4-4

Espoma Garden-Tone Natural & Organic Fertilizer

My first pick is an organic granular, formula from Espoma and it is perfect for growing potatoes if you already have nitrogen-rich soil. The 3-4-4 NPK balance plus exclusive Bio-tone microbes equal a consistent and steady disbursement of nutrition into the soil and can be used for all varieties of potato plants.

This is an easy formula to work with and can even be used if you have worked in aged compost to your soil. It’s a slow-release formula which means you can simply apply the first application in May to new seedlings and then repeat monthly thereafter throughout the growing season. This regular application will ensure that your plants are provided with a continuous source of macronutrients to support healthy growth and a plentiful crop. Check the latest price of Espoma Garden-Tone online here.

How To Use: Work the recommended amount into the soil prior to planting or apply to seedlings 7-10 days after planting. Repeat monthly from May to August.

Customer Reviews: Potato growers are reporting results within just 1 week of application and surprising bumper crops after a full season of using this organic product. Awarding Espoma’s Garden-Tone 4.7 out of 5 stars and my pick for best buy.

Pros      

  • High yields from an organic product
  • Results after just one week

Cons

  • Organic odor may be attractive to pets

2. Miracle-Gro Performance Organics Edibles Plant Nutrition Granules | 7-6-9

Miracle-Gro Performance Organics Edibles Plant Nutrition Granules

This slow-release option from Miracle-Gro is one of my top picks based on ease-of-use and price vs results. Well-known for dependability, Miracle-Gro’s new organic formula brings not only a bumper crop but also the peace of mind that comes from feeding my edibles something natural.

The increased ratio of potassium means you can expect a high yield and also increased resistance to disease as the tubers develop. Added potassium also means your harvest has the potential to keep for longer and be richer in color and flavor when cooked.

If that isn’t enough, this potato fertilizer has an endorsement by the Organic Materials Review Institute and can be used to fertilize pumpkin and other flowering edibles. Click here for details of Miracle-Gro Performance Organics from Amazon.com.

How To Use: The flip lid dispenser makes applying the granules easy and mess-free. Simply shake and pour around the base of your established plants. You will need to measure out your plot beforehand to make sure that you are not overfertilizing. Water as normal and repeat every 4-6 weeks throughout the growing season.

Customer Reviews: Following bountiful results, home-growers are pleased to see a proven organic option from a company whose products they’ve depended on for years. Large and plentiful potato harvests grant Performance Organics 4.6 / 5 stars.

Pros      

  • Vigorous growth and plant vitality with consistent use
  • Increased yield with an organic NPK

Cons

  • Not recommended for use as a water soluble


3. Jobe’s Organics Vegetable and Tomato Plant Food | 2-5-3

Jobe’s Organics Vegetable and Tomato Plant Food

Of course, I can’t put together the best fertilizer list without including Jobe’s Organics. This easy-to-use granular choice employs aggressive micro-organisms that quickly break the granules down, sending nutrients to the roots faster than other slow-release feeds might. Not only will your crops benefit from faster growth and improved soil quality, but the formula also helps plants withstand unfavorable conditions and susceptibility to disease.

I sprinkled Jobe’s Organics in and around my potato crops, early in the season when the foliage hasn’t gotten too dense. The result is rich and luscious bright green foliage in no time. This can also be used for soil preparation in vegetable gardens or containers, and even on tender vegetable seedlings all through the growing season.

This is another fertilizer that comes with an OMRI-listed seal of approval. It means it is certified for organic gardening by USDA and there are no synthetic chemicals incorporated in this product. Click here to buy Jobe’s Organics Vegetable & Tomato Plant Food.

How To Use: Apply 1 ½ cups per foot of plant spread or 2 cups for plants 3 feet or wider.

Customer Reviews: Gardners new to cultivating potatoes have gained new confidence using Jobe’s granules. The vibrant, abundant foliage indicates mass tuber duplication resulting in a bountiful harvest. 4.6 out of 5

Pros      

  • Quick infusion of nutrients using proprietary microbes
  • Lasts up to 6 weeks

Cons

  • May exhibit a slight organic odor

4. Espoma Organic Bone Meal | 3-15-0

Espoma Organic Bone Meal

Espona Organic Bone Meal is a great fertilizer if you need to add phosphorous and calcium to your soil. This can be done prior to planting in order to address low levels of acidity in soil. I tend to use this fertilizer in soil that I am going to plant potatoes in the following year as it’s a slow-release formula that takes time to work effectively.

That being said, new potato crops that I have planted in bone meal fertilized soil really do benefit from the high phosphorus content and you can expect a surge of tuber offshoot growth right out of the gate. With just the right amount of nitrogen for solid stem and tuber formation. Buy Espoma Organic Bone Meal here.

How To Use: Work well into the soil at planting time, in the amount recommended on the label per sq footage.

Customer Reviews: Potato growers who have dogs in their families, as I do, love that this is an organic and safe product to use if they become “interested” in what they’re doing. Highly recommended if you’re going for a high yield. 4.8 out of 5 stars.

Pros      

  • High phosphorus content for maximum tuber replication
  • Only one application required at planting time

Cons

  • Smell may be attractive to dogs after watering

5. Miracle-Gro Shake ‘N Feed Tomato, Fruits and Vegetables | 10-5-15

Miracle-Gro Shake 'N Feed Tomato, Fruits and Vegetables

Miracle-Gro Shake n’ Feed has been a mainstay in my own garden regimen for years thanks to their excellent track record and range of fertilizers. In addition to the specially formulated micronutrients, this potato fertilizer contains an array of natural ingredients that help to feed the microbes in the soil. And it is these microbes together with the nitrogen-focused N-P-K that help to stimulate foliage and tuber growth throughout the growing season.

This feed also contains extra calcium for higher-quality potatoes with a longer shelf life plus protection against crop disorders that can lead to disease or failed crops.

I also find this feed is versatile enough to use in my garden beds as well as containers for all of my flowering edibles. Check prices at Amazon.com for Miracle Shake n’ Feed here.

How to use: I like to use this right at the start of the growing season before the real growing action gets underway. That way, the soil is primed and nutrient-rich ready to support new plant growth when it starts. This product is suitable for growing vegetables in containers and in the ground. Simply scatter the required amount in and around your vegetables once every 3 months during the growing season.

Customer Reviews: Gardeners, who used different feeds for different plants, really appreciate the ease of use and versatility of this product. And the new calcium-added formula is definitely a bonus. 4.7 / 5 stars.

Pros      

  • Versatile enough for use with all garden vegetables
  • New calcium-added formula for higher quality crops

Cons

  • Results may vary in nitrogen-poor soil

6. The Old Farmer’s Almanac Organic Plant Food | 8-4-8

The Old Farmer's Almanac Organic Plant Food

Farmer’s Almanac plant food is OMRI listed and provides both quick and slow-release nutrients for potatoes in all stages of growth. You simply need to mix these granules into compost-amended soil and you won’t need to wait long to see results.

Another bonus of this potato fertilizer is it is an all-in-one organic product with no harsh odor. Old Farmer’s Almanac Organic Plant Food can be purchased here.

How To Use: Following the recommended doses per sq footage, spread granules evenly over your grow area. Repeat every 6-8 weeks.

Customer Reviews: Home-growers are recounting how fast their tubers started sprouting and multiplying when adding this product to freshly amended soil. Even in regions with harsh climates and short growing seasons. 4.5 out of 5 stars.

Pros      

  • No Harsh odors or manure
  • Immediate response in sprouting and tuber multiplication

Cons

  • Over-watering organic feeds may result in fungus growth

 7. Dr. Earth Organic Vegetable Fertilizer | 4-6-3

Dr. Earth Organic Vegetable Fertilizer

Dr. Earth’s Organic fertilizer has a proven track record in effectiveness when used either as a top dressing or as a water-soluble tea. It contains probiotics and seven different types of beneficial microbiotics all of which are said to help potato crops utilize nutrients effectively. The results that I have seen have resulted in twice the overall plant size. 

Click here for Dr. Earth Home Grown Vegetable Fertilizer.

How To Use: For new plantings: add 1 ½ cups to soil prior to planting. For established plants, apply ¾ cup for every 10 sq ft of growing area. Repeat every 2 months.

Customer Reviews:  Consumers are feeling Dr. Earth’s feed is great value for money. Putting it at the top of their “favorites” list. In small gardens, it can last for several growing seasons and the results are far better than other pricier options. Awarding it 4.6 out of 5.

Pros      

  • Great value for money
  • Probiotics and seven beneficial microbiotics

Cons

  • Pets and wildlife may be attracted to the organic smell

8. Miracle-Gro Performance Organics Plant Nutrition | 11-3-8

Miracle-Gro Performance Organics Plant Nutrition

Performance Organics from Miracle-Gro also offers a water-soluble formula consisting of an 11-3-8 NPK and essential micronutrients for the same high yielding results, in less time.  I tried this with both my trusty watering can and hose attachment. Both of which delivered the same performance in organic nourishment as the granule option.

Buy Miracle-Gro Performance Organics Plant Nutrition from Amazon.com here.

How To Use: Add two level scoops to each gallon of water used. Apply once per week for consistent results.

Customer Reviews: Gardeners who are long-time users of Miracle-Gro’s flagship vegetable feed were hesitant to switch to an organic option until they saw the same, dependable results they expected. Reporting they’ll stick to organic now, going forward. Earning this quick-release option 4.6 / 5 stars.

Pros      

  • Quick-release for immediate nutrient absorption
  • Helps to improve nutrient-poor soil

Cons

  • May exhibit a slight organic odor

9. Down to Earth Organic Vegetable Fertilizer | 4-4-4

Down to Earth Organic Vegetable Fertilizer

My final pick is from Down-to-Earth. They strongly encourage the use of natural compost and have created this equal-ratio vegetable feed to perfectly compliment that recommendation. I never have to worry about plant burn when using this and my veggies forever thank me for it. Click here for Down To Earth Organic Veg Fertilizer.

How To Use: Apply ½ cup per sq foot of growing area and work into the top 3” of soil. Repeat twice per month throughout the growing season.

Customer Reviews: Gardeners across many review platforms are raving about the reasonable price and wonderfully organic results they’ve seen using this product. And without the typical odor associated with organic products. Calling it “their secret to success”. 4.7 out of 5.

Pros      

  • Powerful equal-ratio NPK, Gentle enough for heavily amended soil
  • No harsh, organic odor

Cons

  • May be at a slightly higher price point than others

How to Fertilize Potatoes

So, as we’ve seen the best fertilizer for potatoes in your garden could be one product for the whole season or a couple of different types to apply through different stages of development. For an immediate boost in tuber reproduction, introduce a healthy amount of phosphorus at first planting. This will lead to a bumper crop later in the season.

For healthy vines and foliage emerging from all those tubers, an infusion of nitrogen will encourage lush growth, increasing photosynthesis and energy that is sent directly back to the tubers.  Finally potassium, so your plants can efficiently metabolize all the nutrients you give them.

Tips For Fertilizing Potatoes   

Growing potatoes organically isn’t as challenging as some may think. It just requires a little research into soil conditions, understanding what nutrients your tubers need and when, and finally knowing what organic substances you can apply that contain those needed nutrients.  The above options can easily provide those for you without all the fuss.

For those gardening in higher altitudes, potatoes are a perfect crop as they’re actually adapted to higher elevations and harsher growing conditions. If you live in a short-season climate, Queen Anne and Torino potato tubers have fast maturity times, are disease resistant, and have a long shelf life.

Healthy Potatoes    

Modern dietary habits have gotten a bad rap for being too carb-heavy and thus, assumed unhealthy. Yes, carbs do become sugars in the body and can contribute to excess weight if we don’t use those carbs as the energy source they’re meant to be and work them off.

In reality, potatoes are actually nutrient-packed, culinary titans, and absolutely fine if eaten in moderation and as part of a varied diet. In fact, potatoes are actually high in potassium, vitamins, iron and have shown to be important factors in fighting cancer and glaucoma.  They’re not quite the empty-calorie stomach fillers they’ve been made out to be.

Producing More Tubers

Phosphorus, potassium, and calcium have very positive effects on tuber replication. As we’ve discussed, nitrogen also contributes to this by increasing healthy foliage which diverts energy back to those tubers.

A second way to promote a higher yield is how deep you plant your initial tubers. Trenches no more than 8”-10” deep are recommended. You want the main stem coming from each tuber to be as long as possible. The longer it is, the more roots grow from it. Increasing the opportunity for nutrient intake and, of course, more tubers.

Applying Fertilizer to Potatoes

The final step in proper potato fertilization is understanding the kind of potatoes you’re growing. Different types of spuds have different rates of growth and harvest times. When to fertilize and how much will greatly depend on these factors. Let’s take a look at the two main categories.

Potato Plant Fertilizer For First and Second Earlies       

The term “earlies” describes the early harvest times of certain potato varieties. Examples of early potatoes would be the Lady Christl and Rocket varieties. First earlies grow the fastest at 10-12 weeks to harvest,  with second earlies at around 14-16 weeks. These are popular due to them being ready so early and in being so, they are far less prone to blight.

Some phosphorus-rich feeds can be applied at the time of planting,  while other more balanced ones can be applied two weeks after. Continue feeding, per label instructions but stop 2 weeks prior to harvest.

Potato Plant Fertilizer For Maincrop Potatoes

Maincrop potatoes are the largest varieties that take the longest to mature. Anywhere from August to October, depending on how big you want them to get. Examples of these would be Pink Fir Apple, Maris Piper, and Sarpo Mira.

With a longer growing season comes the need for more fertilizer than earlies, roughly 25% more. Phosphorus at the time of planting is crucial for these varieties to reach a maximum size and high yield potential. A steady stream of nitrogen will keep foliage lush and effective in acquiring energy for tubers and potassium to make sure the flow of nutrients is unimpeded.

When to Fertilize Potatoes

To re-cap, depending on the condition of your soil, fertilization could begin from the moment of first planting in spring. How late into the growing season you need to continue fertilizing depends on the variety you’re growing.

How Often Should You Fertilize Potatoes?

How often you feed your spuds will be dependant on the method of application built into your choice of feed. Quick-release options may need to be applied more frequently with the benefit being faster delivery of nutrients.

Slow-release fertilizers may only need to be added every few months for a more gradual stream of nourishment.

Verdict: Best Fertilizer For Potatoes

The verdict is in! The best fertilizer for potatoes growing in your little patch of heaven will be just as unique as you, the gardener who tends them. Specific to your particular soil conditions, climate, potato variety, and application preference.

So, what will it be? Will you choose Espoma Garden-Tone, with its exclusive Bio-tone microbe formulation that ensures a steady flow of nutrients throughout the growing season?

Or, what about good-old, dependable Miracle-Gro Performance Organics? This one has an increased ratio of potassium so you can expect a high yield and also increased resistance to disease.

Alternatively, what about Jobes Organics Vegetable and Tomato Plant Feed? This easy-to-use granular choice brings you aggressive micro-organisms that help to send nutrients to the roots faster than other slow-release feeds might, meaning your crops will grow faster and benefit from improved soil quality.

In my list of picks, I’ve included a variety of different options to meet the needs of your special potato patch for a successful and bountiful harvest. Now it’s down to you to decide.

Potato Fertilizer FAQ