6 Best Fertilizers for Potatoes to Boost Your Tuber Yield
We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation.
Potatoes are one of the highest-yield vegetables that a home gardener can grow, but they do require a specific environment if they’re going to flourish.
One of the best days of my gardening year is when I finally make the decision to pull my potatoes and see how big they’ve gotten. And I’ve never been disappointed since I figured out the perfect potato fertilizer to use while they’re growing.
As I’ll explain below, the best fertilizers for potatoes will have a limited amount of nitrogen. At the beginning of the growing season, potatoes need a fair amount to help get established. But, while your tubers are actually developing, you want to limit the amount of nitrogen in the soil in order to keep the plants from growing external vines and leaves instead of the actual root you’re looking to harvest.
In this article, I’ve found some of the best potato fertilizers that have the perfect balance of nutrients. Any home gardener can grow an excellent crop with the help of these great products.
Read on to find out more!
Key Takeaways
After spending days looking through my own garden shed and researching products online, I came up with this list of 6 of the best fertilizers for potatoes. Overall, the best is Old Cobblers Farm Seed Potato Fertilizer. With a perfect N–P–K for the development of healthy potatoes and slow-release granules that will feed your plants for a long time, it’s a standalone product that can make a huge difference to your yields all by itself.
I’ve also included all-purpose fertilizers that are great for both potatoes and other vegetables, like the Cz Garden Supply Store Tomato & Vegetable Fertilizer, and fertilizers that are great for the early stages of potato development but need to be phased out later in the season, like the Down to Earth Organic Neem Seed Meal Fertilizer Mix.
Best Overall: Old Cobblers Farm Seed Potato Fertilizer
Why This is a Quality Choice: I’ve listed Old Cobblers Farm Seed Potato Fertilizer as the best of the best fertilizers for potatoes because its simple blend of nitrogen, phosphorus, and potassium is exactly what the majority of home gardeners need to increase their yields.
There’s nothing extra added here. And, its long-lasting granules mean that you won’t have to constantly be reapplying this fertilizer throughout the year, saving you plenty of time.
Who is this for? This product is perfect for gardeners who don’t really want to fuss over their potatoes but instead want an easy-to-use product that can help them grow a great crop.
Flaws but not deal-breakers: Since this is a straight N–P–K fertilizer, you might need to consider adding some other organic materials to renew your soil after the growing season is over.
Active ingredients: Nitrogen, phosphorus, potassium | Herbicides: None | N–P–K: 8–16–16 | Package size: 10 lbs
Best Budget: Jobe’s Organics 09026 Fertilizer
Why This is a Quality Choice: This organic vegetable fertilizer from Jobe’s Organics is an excellent choice for gardeners who want to use natural processes to improve their potato yields. It has small yet balanced amounts of nitrogen, phosphorus, and potassium but makes up for this by supporting plant growth with bacteria, mycorrhizal fungi, and archaea. And, despite its organic certification, it’s a very affordable option.
Who is this for? This is a small and affordable bag of fertilizer that gardeners who have only a small patch of land to fertilize can use.
Flaws but not deal-breakers: The coverage area of 120 square feet will be too small for some gardeners, but the small size helps keep the sticker price down.
Active ingredients: Bone meal, poultry manure, sulfate of potash, as well as bacteria, mycorrhizal fungi, and archaea | Herbicides: None | N–P–K: 2–5–3 | Package size: 4 lbs
Best Value: Lilly Miller Morcrop Tomato & Vegetable Food
Why This is a Quality Choice: This 16-pound bag of Lilly Miller Morcrop Tomato & Vegetable Food provides great value for gardeners who have a larger area to fertilize but still want to keep things affordable. Its 5–10–10 NPK offers the perfect ratio for growing potatoes, allowing you to avoid putting too much nitrogen in the soil. And, you can feel good about using its all-natural ingredients.
Who is this for? I’d recommend this fertilizer to gardeners who want to grow a large patch of potatoes and take advantage of great value (0.16 cents per ounce) while doing it.
Flaws but not deal-breakers: The blend of poultry waste and bone meal can have a strong smell to it, especially when it’s first applied.
Active ingredients: Dried poultry waste, bone meal, alfalfa meal, ammonium sulfate, ammonium phosphate, muriate of potash, calcium and sodium borate | Herbicides: None | N–P–K: 5–10–10 | Package size: 16 lbs
Best Early Stage Growth: Down to Earth Organic Neem Seed Meal Fertilizer Mix
Why This is a Quality Choice: The Down to Earth Organic Neem Seed Meal Fertilizer Mix is ideal for supporting the early stages of potato growth with its high-nitrogen N–P–K ratio. Its active ingredient is neem seed meal, which is derived from the organic material a fast-growing tree creates.
I’d recommend applying this fertilizer at the beginning of the growing season before switching to a higher-phosphorus and potassium fertilizer.
Who is this for? If you’ve struggled with getting potatoes to become established and grow in poor-quality soil, you might get a lot of use out of this product.
Flaws but not deal-breakers: Getting the timing right when it comes to using this one and then switching to another fertilizer can be a challenge if you don’t have a lot of experience growing potatoes.
Active ingredients: Neem seed meal | Herbicides: None | N–P–K: 8–16–16 | Package size: 10 lbs
Best Potash Fertilizer: Cz Garden Muriate of Potash
Why This is a Quality Choice: This potash-derived fertilizer is a great way to provide a huge potassium boost to your potato patch late in the growing season. Since the potassium is so concentrated, a little bit of this fertilizer goes a long way, and a single bag can last you an entire growing season even if you have a large amount of potatoes.
Who is this for? If you’re in an area that limits phosphorus use in fertilizers but you still want to add some potassium to the soil, I don’t think there’s a better product for you.
Flaws but not deal-breakers: You’ll need to use a different fertilizer that has nitrogen in it during the early stages of the growing season in order to support the development of your potato plants.
Active ingredients: Muriate of Potash | Herbicides: None | N–P–K: 0–0–60 | Package size: 5 lbs
Best Organic: FoxFarm Happy Frog Garden Tomato and Vegetable
Why This is a Quality Choice: I find that FoxFarm is an excellent producer of organic gardening products, and this all-purpose vegetable fertilizer is no exception. In addition to the standard nutrients, potato plants can benefit from the high levels of organic bacteria that this fertilizer contains.
Who is this for? Gardeners who are passionate about using organic materials should consider using this fertilizer for their potatoes.
Flaws but not deal-breakers: The potassium level of this fertilizer isn’t huge, so some gardeners might want to add some extra using a different product.
Active ingredients: Nitrogen, phosphorus, potassium | Herbicides: None | N–P–K: 5–7–3 | Package size: 4 lbs
Buying Considerations for The Best Fertilizers For Potatoes
N–P–K
As you’ve seen throughout this article, the N–P–K of a potato fertilizer is absolutely essential for when and how you use it. Potatoes need nitrogen to help them establish strong root and vine systems but then benefit more from phosphorus and potassium once the tubers start developing.
That means you should either use a low-nitrogen fertilizer throughout the entire growing season or start out with something that has plenty of nitrogen and then switch to a low nitrogen, high phosphorus and potassium fertilizer a month or six weeks into the growing season. Both approaches can yield great results; the main difference is in the amount of complexity you’re ok with while gardening.
Soil Conditions
The pre-existing soil conditions at the start of the growing season also make a huge difference to which fertilizer will be the best for you. If, like many gardeners, you apply compost and manure to your growing area, you won’t need to boost the nitrogen in your soil to help kickstart your potatoes—there will be enough for them already.
Another important question is how much phosphorus is naturally in your soil. If the levels aren’t particularly high, you should use a balanced fertilizer like Old Cobblers Farm Seed Potato Fertilizer or Cz Garden Supply Store Tomato & Vegetable Fertilizer. But, if a soil test reveals that you have plenty of phosphorus, you can use a potassium-only option like Cz Garden Muriate of Potash.
Ingredients
Many gardeners will prefer to use fertilizers that have certain types of ingredients based on their values and experiences. Some gardeners will use only fertilizers made from organic compounds on their land, but others have no issue with non-organic fertilizers.
Although the results of the nutrients in an organic or non-organic fertilizer will be the same, some might find that organic fertilizers (like the FoxFarm Happy Frog Garden Tomato and Vegetable fertilizer on this list) have other benefits, such as helping out the microbiome of a growing environment.
How I Choose These Products
In recommending the best fertilizers for potatoes, I tried to get a wide breadth of different types of fertilizers onto this list because what’s going to work best for supporting potatoes differs a lot based on the specific environment you’re going to be growing them in. For that reason, it was important that you read about options like the potassium-only Cz Garden Muriate of Potash as well as balanced fertilizers.
Of course, I did include lots of the latter as well, and in the best overall (Old Cobblers Farm Seed Potato Fertilizer) spot at that. When it came to recommending specific options for the best fertilizers for potatoes, I relied on my own experience of these products as well as brand reputation to decide on exactly which all-purpose or early-stage fertilizer to recommend.
I hope that you’ve learned something about how to get higher yields from your potatoes and found some specific products that will work for you by reading this article!
Final Verdict
Overall, Old Cobblers Farm Seed Potato Fertilizer is the best fertilizer for potatoes that you can buy online. I love the fact that it was specifically formulated to help potatoes grow and has an ideal N–P–K of 8–16–16. If you’re looking to pick up a single fertilizer that has everything your potatoes could ever need, it’s the perfect product for you.
FAQs
What fertilizer does potato need?
The best fertilizers for potatoes will include plenty of phosphorus and potassium to promote strong tuber growth but only limited amounts of nitrogen. That’s because potatoes tend to grow a lot of leaves and vines when they have access to too much nitrogen, which can leave the roots (and tubers) underdeveloped. That means you should use a fertilizer that was specifically created for potatoes or vegetables more broadly rather than something more similar to an indoor fertilizer.
How do you increase the yield of a potato?
Ensuring that potatoes have access to the nutrients they need is the best way to increase yields. Using a potato fertilizer on this list will help you improve your yields quickly and without a lot of extra work. To achieve the best results, you should perform a soil test (or fill your grow bags with high-quality soil) and then select the product that has high values of the nutrient(s) your soil is lacking.
When should I fertilize my potatoes?
You should fertilize your potatoes throughout the growing season, since potatoes need high levels of nutrients to develop healthfully. It’s important that your potatoes can access plenty of nitrogen, phosphorus, and potassium during the early stages of growth, whereas they need more phosphorus and potassium during the later stages of growth. I’d recommend using a potato fertilizer at the same time you’re planting them and then adding more fertilizer or plant food when the first application wears off.
