Best Fertilizer for Pumpkins to Grow in Your Backyard

If you want to grow pumpkins, you’ll need to know the best fertilizer for pumpkins to grow in your garden.

You might be growing it to make one of dozens or so dishes that can be made with pumpkins, or you’re preparing for Halloween. Or both!

Either way, growing these giant fruits is no joke. So you’d want to get it right by using the right fertilizer to grow them well.

In this article, I’ll highlight the best fertilizer for pumpkins and what it takes to grow them bigger. 

Learn about the best fertilizer for pumpkins

Watering and Fertilization of Pumpkins

Pumpkins require a large amount of irrigation. 

They are thirsty plants, and like the other vegetables, they absorb large amounts of essential nutrients from the soil. 

This is why, aside from watering, you need to pay attention to fertilization while growing pumpkins.

I’ll help you get acquainted with the watering and fertilization process for growing these large fruits:

1. Watering

watering pumpkins in the backyard

Before you water the soil, don’t forget to check soil moisture. 

It’s an important factor for growing large pumpkins. If your soil seems to contain large traces of clay, you won’t need to water too frequently. It’s because clay soil can hold water for a longer period.

To check the moisture status, simply insert your finger up to an inch into the land (without damaging the roots). If you feel that your finger is dry, then it’s time to water them.

While watering, you should do it slowly to avoid causing soil erosion. Also, don’t spray water on the leaves as it can develop diseases by attracting pests. 

Try to water them during the morning hours when the evaporation rate is lower.

2. Fertilization

Since pumpkins are heavy feeders, you must supply adequate fertilizer along with water. 

Before planting pumpkins, always incorporate decomposed organic materials into the soil. It will help to improve soil health.

When the plant has taken root and starts to grow, you should fertilize them every month. It’s a good idea to use organic fertilizer for pumpkins. A balanced fertilizer will accelerate the flowering process. 

pumpkin seedling starting to grow

The best fertilizer for pumpkins should contain low nitrogen and high potassium and phosphorus. Fertilizer ratios of 8-24-24 or 5-15-15 work best for these plants. 

A fertilizer with a 5-15-15 label indicates that it contains 5% nitrogen, 15% phosphorus, and 15% potassium. It’s actually a ratio of N-P-K (nitrogen-phosphorus-potassium). Using a 5-15-15 fertilizer for pumpkins means that you are using the above-mentioned percentage of N, P, and K for your plants.

Using fertilizers loaded with nitrogen can result in only plant growth without enhancing the flowering or fruiting process.

Rate of Fertilizer to Apply

After buying the fertilizer and before applying it to your soil, read and follow the manufacturer’s instructions carefully. 

Generally, it’s recommended to apply one and a half (1 1/2) pound fertilizer per 100 feet square.

Scatter the granular fertilizer around the plant. The granules should never be applied too close to the plants as they may cause toxicity.

You can also opt for liquid fertilizer for pumpkins. Most liquid fertilizers have all the nutrients that are needed by plants.

Note: Fertilizers should be applied to the soil rather than to the plant.

When to Fertilize Pumpkins

If you’re new to this, you might be wondering when would be the best time to fertilize your pumpkins.

For fertilization, you’ll need to divide the entire growing period into three phases:

  1. Pre-flowering
  2. Flowering
  3. Fruiting

The plant requires different doses of fertilizer and nutrients in each phase. 


pumpkin pre-flowering

Pumpkin plants usually start flowering in 55 days. In the pre-flowering period, you have to make sure that the plant has received enough nitrogen for its growth. 

Add blood meal to the soil if it has nitrogen deficiency. If the soil seems to be deficient in nitrogen, phosphorus, and potassium, then use 10-10-10 balanced fertilizer.


pumpkin flower

Flowering starts after 55 days of germination. In this phase, the plants produce blooms.

In this phase, you must apply phosphorus or the flowers will become weak. Phosphorus helps the plant to produce the energy that is needed for producing fruits and buds.

In this phase, you should stop supplying excess nitrogen to the pumpkins.


pumpkins fruiting

This is the time when you should focus on providing potassium. Both phosphorus and potassium help the plants to produce ATP. 

Potassium regulates the amount of carbohydrates and water stored in the tissues. In this period, you should provide 5-10-10 NPK fertilizer to boost the fruiting process. Potassium also helps the fruits to grow bigger and more fleshy.

Best Fertilizer for Pumpkins

In this section, I will discuss the best fertilizers for pumpkins, especially organic and natural fertilizers. They are mostly harmless and free from toxic compounds.

1. Blood Meal and Bone Meal

blood meal fertilizer

Blood meal is simply dried blood of cattle. To make this, you need to collect blood from a slaughterhouse and dry it. Then you can make it in powder form.

It is rich in nitrogen. So, I assume that you have understood when to apply this one.

Bone meal is the powdered form of cattle’s bones. You can also use fishbone for this as it is a great source of phosphorus. It’s considered the best fertilizer for giant pumpkins.

While using them, don’t apply too close to the plant. 

2. Manure or Liquid Manure

You may be well-familiar with manure. But what is liquid manure?

Liquid manure can be prepared by the fermentation of the manure. It means you only need to leave the manure in submerged condition underwater for a few days. 

It’s better to use a bucket for preparing liquid manure. It is rich in nitrogen and potassium.

3. Seaweed or Kelp

seaweed or kelp as pumpkin fertilizer

Supplying seaweed to the pumpkins is the quickest way to provide phosphorus and potassium. It has a complete package of minerals that pumpkins need. 

However, you need to treat these weeds before using them. Rinse it properly to remove salts.

Frequently Asked Questions (FAQs)

Is 10-10-10 fertilizer the best fertilizer for pumpkins?

10-10-10 fertilizer indicates 10% N, 10% P, and 10% K. It is better to use fertilizers with greater percentages of P and K. However, if your soil has N, P, and K deficiency, then I recommend using 10-10-10 fertilizer.

Can I use potassium rich fertilizer for pumpkins?

Yes. Potassium rich fertilizer boosts the fruiting process.

When should I use potassium rich fertilizer?

You need to use potassium rich fertilizer when fruits start appearing.

Where do pumpkins grow best?

Pumpkins grow best under the full sun and moist soil.

Final Thoughts

I hope that this article will help you to choose the best fertilizer for pumpkins. 

With this knowledge in hand, you can now grow these vegetables larger and make them more fleshy by providing the right amount of nutrients.

Once the fruit is ripened, use them well. I suggest you try roasting the pumpkin seeds. They make for amazing treats! Not to mention it’s incredibly nutritious.