Best Fertilizer For Watermelons of 2024: Top 6 Picks

By Harry RamosLast update: 2024-04-21

Looking to grow juicy, delicious watermelons in your garden? Well, apart from proper care and attention, the right fertilizer can work wonders. A good fertilizer not only promotes healthy plant growth but also improves yield and flavor.

But with so many options available in the market, finding the best one for your watermelon crop can be a daunting task. That's why we've put together this guide on some of the most popular fertilizers for watermelons that are sure to give you an abundant harvest!

Here are the best fertilizers for watermelons you can buy in 2024:

  • Best For Drought-Tolerant Crops: Neptune's Harvest N17 TV191
  • Best For Preventing Blossom-End Rot: Miracle-Gro 3002610
  • Best For Flowering Watermelons: Miracle-Gro 3005510
  • Best For All Growth Stages: Triple 10 All Purpose Liquid Fertilizer 10-10-10
  • Best For More Nutritious And Tasty Fruits: Dr. Earth 704P
  • Best For Strong Roots: Southern Ag PowerPak 20-20-20
6 Best Fertilizers For Watermelons
Best For Drought-Tolerant Crops
Neptune's Harvest N17 TV191
    Best For Preventing Blossom-End Rot
    Miracle-Gro 3002610
      Best For Flowering Watermelons
      Miracle-Gro 3005510
        Best For All Growth Stages
        Triple 10 All Purpose Liquid Fertilizer 10-10-10
          Best For More Nutritious And Tasty Fruits
          Dr. Earth 704P
            Best For Strong Roots
            Southern Ag PowerPak 20-20-20

              Best For Drought-Tolerant Crops: Neptune's Harvest N17 TV191

              Neptune's Harvest N17 TV191
              Neptune's Harvest N17 TV191
              Pros
              • Increase the water-holding capacity of the soil – humic acids
              • Provide a slow-release source of nutrition for watermelons - nitrogen component from fish protein
              Cons
              • It has bad smells

              If you're looking for an organic fertilizer that can increase the drought tolerance of your watermelon crops, then use Neptune's Harvest N17 TV191.

              It's formulated from humic acids, yucca extract, molasses, seaweed, and fish. All are known for their ability to help plants withstand periods of low water availability.

              The nitrogen component is derived from fish protein, which breaks down slowly into basic nitrogen compounds, providing a slow-release source of nutrition for the plant. This slower release helps to extend the amount of time between waterings and also helps retain moisture in the soil.

              Meanwhile, the humic acids can help to increase the water-holding capacity of the soil, further aiding in drought tolerance.

              Neptune's Harvest N17 TV191 Specifications

              Size

              1 Gallon (8.8 Pounds)

              Fertilizer Analysis

              2-4-2

              Coverage

              ~ 8000 sq. ft.

              Highlight Features

              humic acids

              nitrogen component from fish protein

              Verdict

              The Neptune's Harvest N17 TV191 is the best choice for drought-tolerant watermelon crops that you can find on the market.

              Best For Preventing Blossom-End Rot: Miracle-Gro 3002610

              Miracle-Gro 3002610
              Miracle-Gro 3002610
              Pros
              • Prevent blossom-end rot in watermelons – ability to keep the soil pH balanced
              • Stimulate healthy growth – 10% nitrogen
              • Increase fruit production – 15% potassium
              Cons
              • The granules are so big
              • It’s prone to overfeed

              There are many fertilizers out there advertising to prevent blossom-end rot in watermelons. But we find the Miracle-Gro 3002610 to be the best performer.

              Blossom-end rot occurs when the soil pH is too acidic or too alkaline and causes the fruits of the watermelon to be undersized, misshapen, and discolored.

              This fertilizer helps to keep the soil pH balanced, which is important for ensuring that the roots are able to absorb the necessary nutrients from the soil.

              It also helps to provide essential nutrients to the plant which can help to stimulate healthy growth and increase fruit production.

              Miracle-Gro 3002610 Specifications

              Size

              4.5 lbs. (4.5 Liters)

              Fertilizer Analysis

              10-5-15

              Coverage

              128 sq. ft.

              Highlight Features

              ability to keep the soil pH balanced

              Verdict

              By providing the necessary nutrients and maintaining a balanced soil pH, the Miracle-Gro 3002610 can help to reduce the risk of blossom-end rot in your watermelon plants.

              Best For Flowering Watermelons: Miracle-Gro 3005510

              Miracle-Gro 3005510
              Miracle-Gro 3005510
              Pros
              • Good for flowering watermelons – 6% phosphorus & 9% potassium
              • Safe and high-quality - OMRI listed
              • Comfortable to use – a bottle design with a comfortable handle
              Cons
              • Wish the granules were smaller for more even spreading and results

              The Miracle-Gro 3005510 is a granular fertilizer that contains a combination of essential nutrients for growing strong and healthy watermelon plants.

              It's especially rich in phosphorus and potassium which promote strong root development, and abundant fruit and flower production.

              In addition, the inclusion of beneficial microorganisms helps improve the soil structure and increase nutrient availability.

              This fertilizer is OMRI listed, so you can rest assured about its safety and quality. Its bottle design with a comfortable handle and a big cap is also a big plus.

              Miracle-Gro 3005510 Specifications

              Size

              2.5 lbs.

              Fertilizer Analysis

              7-6-9

              Coverage

              220 sq. ft.

              Highlight Features

              6% phosphorus & 9% potassium

              OMRI listed

              a bottle design with a comfortable handle

              Verdict

              The Miracle-Gro 3005510 is an ideal fertilizer for flowering watermelons. It ensures the plants have access to all the nutrients they need for flowering and fruiting.

              Best For All Growth Stages: Triple 10 All Purpose Liquid Fertilizer 10-10-10

              Triple 10 All Purpose Liquid Fertilizer 10-10-10
              Triple 10 All Purpose Liquid Fertilizer 10-10-10
              Pros
              • Good for all growth stages – a balanced 10-10-10 NPK ratio
              • Easy to measure and use – the bottle with a built-in measuring device
              Cons
              • A bit expensive

              The Triple 10 All Purpose Liquid Fertilizer stands out due to its balance of nutrients, amino acids, and seaweed extract. This helps to elevate the quality of soil and provide watermelons with the essential nutrients they need during their various growth stages.

              The 10-10-10 NPK ratio is considered an all-purpose balanced fertilizer that can be used for a variety of watermelons.

              During the growing season, it is recommended to reapply the fertilizer every 30 days to ensure that plants are receiving the necessary nutrients they need.

              Additionally, this fertilizer can also be used as a lawn-feeding fertilizer as well.

              Triple 10 All Purpose Liquid Fertilizer 10-10-10 Specifications

              Size

              0.94 Liters (32 Ounces)

              Fertilizer Analysis

              10-10-10

              Coverage

              1,000 square feet with the mixing ratios.

              Highlight Features

              a balanced 10-10-10 NPK ratio

              the bottle with a built-in measuring device

              Verdict

              If you’re looking for a fertilizer for all growth stages of watermelons, our favorite pick is the Triple 10 All Purpose Liquid Fertilizer

              Best For More Nutritious And Tasty Fruits: Dr. Earth 704P

              Dr. Earth 704P
              Dr. Earth 704P
              Pros
              • Help plants produce more nutritious and tasty fruits – contain ecto and endo mycorrhizae, and beneficial soil microbes
              • Safe to use – contain no sewage sludge, chicken manure, or GMOs
              • Easy to store – the zipper bag
              Cons
              • The fertilizer has bad odors
              • A bit pricey

              The Dr. Earth 704P can help watermelon plants produce more nutritious and tasty fruits.

              The fertilizer is designed to provide optimum levels of nutrients for all kinds of vegetables and herbs, including watermelons. It contains beneficial microorganisms, humates, natural plant extracts, and select minerals that can improve the health and productivity of your watermelon plants.

              The fertilizer should be applied every other month throughout the growing season. For established plants, top-dress with one cup for every 10 square feet of growing area.

              Although the fertilizer is safe, it's important to monitor your pet if they ingest a large amount to prevent any upset stomachs.

              Dr. Earth 704P Specifications

              Size

              4 Pounds

              Fertilizer Analysis

              4-6-3

              Coverage

              60 sq. ft.

              Highlight Features

              contain ecto and endo mycorrhizae, and beneficial soil microbes

              no sewage sludge, chicken manure, or GMOs

              the zipper bag

              Verdict

              We heartily recommend the Dr. Earth 704P for watermelon gardeners who want their plants to produce more nutritious and tasty fruits.

              Best For Strong Roots: Southern Ag PowerPak 20-20-20

              Southern Ag PowerPak 20-20-20
              Southern Ag PowerPak 20-20-20
              Pros
              • Promote strong roots – 20% phosphorus
              • Optimize plant growth and health – contain micronutrients
              Cons
              • Wish it came with a measuring cup

              Watermelon plants require a balance of nutrients to develop strong roots. And the Southern Ag PowerPak 20-20-20 is everything they need.

              It contains equal amounts of nitrogen (20%), phosphorus (20%), and potassium (20%), so it provides the balanced formula that watermelons need to develop strong roots and other parts of the plant.

              The fertilizer also contains micronutrients that help to optimize plant growth and health, making it an ideal fertilizer for watermelons.

              To use this fertilizer for watermelons, it should be applied every two weeks throughout the growing season, starting when the seedlings are about 4-6 inches tall.

              Southern Ag PowerPak 20-20-20 Specifications

              Size

              5 Pounds

              Fertilizer Analysis

              20-20-20

              Coverage

              5000 square feet with the mixing ratios.

              Highlight Features

              20% phosphorus

              Verdict

              The Southern Ag PowerPak 20-20-20 is the best all-purpose fertilizer for strong roots you can buy.

              How To Choose The Best Fertilizer For Watermelons?

              Native Soil Conditions And Texture Of The Garden

              When selecting the best fertilizer for watermelons, it is important to consider the native soil condition and texture of the garden.

              Why? Because different soil conditions create different needs for fertilizer.

              Different textures of soil may also require different types of fertilizer, so be sure to choose a fertilizer that is specifically tailored to the soil type in your garden.

              Nutrient Content Of The Fertilizer

              Always consider the nutrient content of the fertilizer you will use.

              Different fertilizers contain different levels of essential nutrients such as nitrogen, phosphorus, and potassium (NPK), and some may also contain additional trace minerals or micronutrients.

              When selecting a fertilizer, be sure to select one that contains a balance of these essential nutrients in order to promote healthy growth and development.

              Quick-Release Or Slow-Release Formula?

              It depends on the amount of time you plan to spend tending to your watermelon plants.

              If you plan to spend a lot of time tending to your plants, you may want to use a quick-release fertilizer with higher nutrient content.

              On the opposite, if you are only looking for minimal maintenance, slow-release fertilizer with lower nutrient content may suffice.

              Additionally, depending on the type of fertilizer you choose, you may need to apply it multiple times throughout the season.

              Which Brands Make The Best Fertilizer For Watermelons?

              Neptune's Harvest

              Is Neptune's Harvest a good brand of fertilizers for watermelons? Absolutely!

              Neptune's Harvest is a great brand of fertilizer for watermelons and other fruits and vegetables. They offer many fertilizer lines that provide an instant release of nutrients to watermelon plants. All of these products are made from high-quality and organic ingredients, which ensures quality.

              Dr. Earth

              Dr. Earth offers some specifically formulated fertilizers for the optimal growth and health of watermelon plants.

              Not only containing a balanced blend of nitrogen, phosphorus, and potassium, as well as additional minerals, their products also have beneficial bacteria that help improve the soil and increase its ability to hold moisture.

              Furthermore, Dr. Earth's formulations are made with organic ingredients, so you can be sure your garden is getting the best nutrition without any synthetic chemicals or additives.

              FAQs

              Do watermelons need lots of nitrogen?

              No, watermelons do not need a lot of nitrogen. In fact, too much nitrogen can create excessive vine growth and reduce the quality of the fruit. Instead, they require ample potassium and phosphorus for optimal melon production.

              How often should I fertilize watermelons?

              Watermelons should be fertilized every 2 weeks when they are actively growing.

              How do I fertilize watermelons?

              Watermelon plants need approximately 1 1/2 pounds (680 g.) of fertilizer for every 100 square feet (9 sq. m.) of garden space. Compost, manure, and chemical fertilizers can all be effective. But it’s important to determine soil conditions in your garden to pick the right type.

              How much fertilizer does a watermelon need?

              When applying the fertilizer, the recommended rate is 1 cup of fertilizer per 10 square feet of soil surface, applying it in a circular band around the plant. Make sure to rake the fertilizer into the top 2-3 inches of soil and water deeply after application.

              Can fertilizer increase the size of a watermelon?

              Yes, fertilizer can increase the size of a watermelon. To achieve this, it is important to provide the correct amount of nutrients to the soil and plants, including nitrogen, phosphorus, and potassium.

              Additionally, providing adequate light, water, and pollination can help ensure larger fruit size.

              Conclusion

              In conclusion, fertilizing watermelons is an important part of ensuring a successful harvest. The right fertilizer can help your plants grow bigger and tastier fruits that you can enjoy all summer long.

              From organic products to synthetic brands, there is certainly a fertilizer for everyone's needs and budget. We hope this article has helped you determine the best fertilizer for watermelons.

              Thanks for reading!

              I’m Harry Ramos, who's crazy about all things green. I’m here to share some experience in my gardening adventure and how to choose the best products for your garden. Let's dig in, get our hands dirty, and celebrate the simple, earthy pleasures of the garden together!


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