Best Fertilizer To Grow Watermelon Fast & BIG – 2022 (Reviews)

Growing large watermelons in your garden is a complex effort but rewards in the form of fun summer days with the family in the backyard or at a picnic.

All you need to do is to provide the plants with adequate light, water, and proper fertilizer doses.

Watermelon plants thrive with a fertilizer NPK ratio of 10-10-10 or 20-20-20 and a soil pH between 6.0 and 6.8.

It is a tasty, fresh and juicy fruit that can grow easily in your home garden but the extra care needed is the supply of the essential nutrients.

The main thing watermelons need is the sun and heat.

You can enhance their growth by putting plastic mulches on the soil and raising the temperature. 

As they are juicy fruits so the adequate supply of water is the main concern after the fertilizer.

If the plant is stressed by the less amount of nutrients at the root zone they will not grow and will not set the fruiting.

So, if you are searching to know how to grow watermelons then keep in mind that proper nutrient fertilizer is the main factor for attaining the desired growth.

In this article, we added some popular fertilizer products that can boost up the growth and fruiting of your plants.


Buyer’s Guide : Choose the Best Fertilizer For Growing Watermelon Plants

When you are deciding on fertilizer for the watermelons then keep in mind the growth habit and food requirements of the watermelon plant according to the growth stages.

The watermelon plant needs nitrogen at most at the onset of fertilization.

Nitrogen is the main nutrient the melons required before the onset of flowering.

Feed the plants with proper nitrogen amounts to enhance the growth of the vines.

Longer veins will produce more flowers which ultimately produce more fruit. 

Phosphorus is the basic need of the plant to promote fruiting. So adding the phosphorus-rich fertilizer will enhance the fruit quantity in your garden.

Once the flowering is onset then phosphorus and potassium are also required at the same rate by the plant.

At that time the balanced fertilizer in the form of 10-10-10 or 20-20-20 having all the basic nutrients in equal proportion is required for fruit production.

In our list, all the required fertilizers are added by our experts. We hope that you will find your desired fertilizer easily.

Reviews: Watermelon Fertilizer

1. J R Peters Jacks Classic No.1.5 20-20-20 All Purpose Fertilizer – 52024

JR Peters is a well-known company for producing the best quality plant food.

In the same way, this plant food product of JR Peters comes with a balanced proportion of NPK as indicated by the product name.

The 20-20-20 formula of this product also has traces of minor nutrients in it i.e Copper, Boron, Chelated Copper Iron, Chelated Iron manganese, and Chelated Manganese Molybdenum, and zinc.

The best thing about this product is that it can be fed both by roots and leaves. Upon entering the plant it will promote leaf expansion.

All of these nutrients will improve the performance of plants by being readily available at the root zone. These nutrients enhance green material expansion and growth.

  • Dissolves faster
  • Formulated for root and shoot growth
  • Fast green-up and expansion
  • Chelated formulas for improved performance
  • Can be applied after the onset of flowering

2. Grow More 5705 Water Soluble Fertilizer 30-10-10

As we know that the green parts of the plant need the nitrogen nutrient the most to maximize growth.

So the Grow More 5705 is the best fertilizer to apply during the vegetative growth of the plants.

Grow more is producing soluble fertilizers for ages and the results are the key features of their publicity.

This nitrogen-rich fertilizer has a good proportion of NPK as 30-10-10 which shows that the product also has the potash and phosphorus nutrient to promote the root growth and plant’s health.

The best thing about this product is its water solubilizing feature which shows that it can be applied both through the roots and leaves.

It is well formulated to supply the plants with essential nutrients that can boost their growth with the high solubility and purity of the ingredients.

This high nitrogen formula is well suited to apply during the spring and early summer.

  • High Solubility
  • Water-soluble
  • Nitrogen-rich formula
  • Boost the plant growth
  • Only good for plant growth

3. Dr. Earth 708P Organic 9 Fruit Tree Fertilizer In Poly Bag

A true gardener must listen to the name of Dr. Earth very often as they are famous for producing organic foods for the plants for many years.

As the name indicates, it is well-suited fertilizer for all fruit trees. The organic ingredients in this product are best to stimulate healthy root development.

It is prepared organically with 100% pure organic and natural ingredients with a trace of chicken manure or sewage sludge.

The best thing about this product is its Non-GMO feature and the presence of pro-biotics with seven strains of the beneficial soil microbes addition with ecto and endo mycorrhizae which stimulates the root development to ensure better plant growth and development.

Once this fertilizer is applied to the fruits it will keep the nutrients supply to them for months.

The slow-releasing feature of this product ensures an increase in soil health and fertility with time.

The fruits obtained from the plants applied with Dr. Earth organic fertilizer will be more nutritious due to the consistent plant growth without any growth spikes.

  • 100% organic and natural ingredients
  • Non-GMO
  • Contains mycorrhizae to promote soil health
  • Promotes healthy root development
  • Better to mixed in soil at preparation before planting

4. Lilly Miller Morcrop Tomato & Vegetable Food 5-10-10

This product by Lilly Miller is formulated especially for tomatoes and vegetables.

From the name, if you are thinking that it is just for the tomatoes then you should know that it is good for all vegetable plants.

This Morcrop product by Lilly Miller has the right combination of NPK as 5-10-10 which completely matches the required nutrient ratio of watermelon plants.

As the watermelon required Phosphorus and potash in more quantity than nitrogen at the fruit development stage so this food will help your plants to produce bigger sized and juicy fruits.

The best thing about this product is that it is fortified with essential nutrients and the slow and fast releasing of the nutrients according to the plant’s need. 

It comes in the packing of 4 pounds containing the all required nutrients to produce better-tasted fruits and lush green plants of tomato and vegetables.

  • Fortified with essential plant minerals
  • NPK ratio well suited for watermelons
  • Slow and quick release of nitrogen
  • Only best for outdoor applicationsn

5. JR Peters 77160 Blossom Booster 10-30-20 Fertilizer

The qualities of JR Peters are discussed earlier in a product so now you do not need to worry about the work of their products.

If you are thinking that we added this blossom booster product to our list mistakenly then you should know that we added this product on purpose.

As the name indicates the proportion of the nutrients in this formulation best matches the required nutrients for watermelons.

The high proportion of phosphorus will promote flower formation and these flowers on reproduction become the fruit so you do not need to worry about applying this fertilizer to your plants.

The best thing about this product is that it stimulates the good use of nutrients present already in the soil. It is named the best fertilizer for vegetable production.

The high proportion of potash in the formulation will help to promote fruit growth and ultimately high yield in the form of healthy and bigger melons.

  • High proportion of Phosphorus and potash
  • Good for promoting the flower formation
  • Great for vegetable productionn
  • Low nitrogen proportion for other plants use

6. Miracle-Gro Water Soluble All Purpose Plant Food, 10 lb

If you are doing gardening for a while then you must have listened to the name of Miracle-Gro.

They are producing plant feeds for many years and are doing very successful businesses across the globe.

In the same way, this product by Miracle-Gro has also a good name as the plant food for vast types of plants.

This water-soluble plant food enriches with full of essential nutrients that instantly feed the plants and make them grow bigger and more beautiful.

The best thing about this product is the water solubilizing nature of the food which makes the food easy to apply both through the soil and leaves. 

The application is very simple as you just need to mix 1 tablespoon of plant food per gallon of water and feed the plants while watering.

It is best to apply to all types of vegetables, trees, houseplants, and shrubs. 

The food is safer to apply as it guarantees to not burn the plants when applied as directed.

  • Water-soluble productnFor all vegetables and treesnWorks like a miracle as its namenBigger, bountiful vegetablesn
  • Just use it as directed and it will not be a problemn

Additional care to promote watermelon growth


Compost is a good addition to the soil especially if you are planning to grow watermelons.

As watermelons love to grow in moist, fertile, and well-drained soil and compost will help your garden soil to keep the moisture for a long time while also improving the soil structure.

For better results, apply the 4-inches layer of compost and mix it into the upper 6 inches of the soil.


Mulch is also a good addition when are planning to conserve moisture for a long time in the soil.

A mulch of any type will help to improve the soil moisture retention ability and prevents the growth of the weed.

The best mulches to apply for the watermelons are shredded newspaper, weeds-free straw, and grass clippings. 

The application of mulch is simple as you just need to apply and maintain the mulch layer on the soil surface.

Avoid overwatering

While growing the watermelons, try to avoid overwatering the plants. The overwatering of the melon plants will cause them to collapse due to the lack of oxygen. 

So to avoid overwatering always check the soil moisture condition before watering.


Should I be cutting/pruning watermelon vines?

Pruning of the watermelon plants can be a good task if the vines are intermingling with each other and you see that they will not thrive completely due to less area. 
The pruning will improve the fruit size and also promotes healthier vines. The cutting back of watermelon plants will cause the plants to send out additional runners.

How often should you fertilize watermelon plants?

Fertilizing of watermelons is very simple as you just need to fertilize the plants with liquid soluble fertilizer once a week.
In the vegetative growth up to the flower initiation you just need to fertilize the plants with more nitrogen fertilizer and after flowering with a balanced fertilizer. 

Is watermelon full of sugar?

No, the watermelon does not contain fruit sugar-fructose. Due to its sweetened taste, some people think of it full of sugar but that is totally wrong.

How do you increase watermelon fruit size?

To improve the size of the melons, you need to follow the following steps:

  1. Water the plants to keep the soil moist
  2. Apply the fertilizer as side-dressing to watermelon plants

The fertilizer will encourage the growth to produce larger melons.


We hope that you have chosen the best plant food for your watermelon plants. We added all the best products available in the market to our list.

All these products will help your plants to thrive and help them to produce the tastier and juicy bigger melons.

We will keep updating our list of any new effective product that comes to the market for the watermelons.

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1 thought on “Best Fertilizer To Grow Watermelon Fast & BIG – 2022 (Reviews)”

  1. thanks very much i am new to this watermelon garden planting.
    my plants are already showing flowers and fruits. now i will be spraying with npk 20.20.20


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