The Ultimate Guide to Transforming Granular Fertilizer into Liquid

Every gardener knows the importance of choosing the right fertilizer for their crops. Among the various options available, granular and liquid fertilizers have emerged as the most popular choices. The question is, which form of fertilizer is more effective? And can we convert one form into another? Today, we dive deep into the world of fertilizers.

Understanding Granular and Liquid Fertilizers

Granular fertilizers are dry pellets made using substances like potassium nitrate, ammonium sulfate, and urea ammonium nitrate. On the other hand, liquid fertilizers are soluble in water and contain nutrients such as potassium chloride and anhydrous ammonia.

Now, let’s explore the pros and cons of each type of fertilizer.

The Pros and Cons of Granular Fertilizers

Granular fertilizers offer several advantages, including:

  • Easy storage
  • Suitable for heavy-feeding plants
  • Cost-effective when purchased in bulk
  • Reduced leaching and drainage from the soil
  • Varieties with slow-release properties, providing prolonged nourishment to plants

However, there are also some downsides to using granular fertilizers:

  • Not suitable for foliar feeding
  • Immobile nutrients may not be accessible to plants
  • Incorrect application can result in leaf burn
  • Only applicable in conventional farming (planting in soil)

The Pros and Cons of Liquid Fertilizers

Liquid fertilizers come with their own set of benefits, such as:

  • Immediate availability of nutrients
  • Usable in hydroponic systems
  • Stimulate rapid growth in young plants
  • Suitable for foliar feeding
  • Effective for quickly correcting nutrient deficiencies
  • Easy dilution to control nutrient levels
Further reading:  The Secret to a Thriving Lawn: Decoding 19-19-19 Fertilizer

However, there are a few drawbacks to using liquid fertilizers:

  • Challenging storage requirements
  • Prone to leaching from the soil
  • Potential risk of leaf burn if not used cautiously

Key Differences Between Liquid and Granular Fertilizers

Apart from their physical forms, granular and liquid fertilizers have several distinguishing features:


Granular fertilizers are generally more cost-effective compared to liquid fertilizers. According to New Mexico State University, the average cost of anhydrous ammonia, commonly used in liquid fertilizers, is $697 per ton. In contrast, the cost of ingredients for granular fertilizers ranges from $456 to $675 per ton.

Method of Dispersal

Granular fertilizers are typically applied on or below the surface of the soil, in the root zone or around seeds. Depending on the type of granules, they may need to be applied every six to eight weeks or can provide slow-release nourishment over an extended period.

Liquid fertilizers, on the other hand, offer more flexibility in application methods. They can be applied to the soil, sprayed on leaves for foliar feeding, or mixed with irrigation water (fertigation) for simultaneous watering and feeding.

Nutrient Availability

Liquid fertilizers provide readily available nutrients to plants, while granular fertilizers come in both slow-release and fast-release variations. The slow-release granules ensure a continuous supply of nutrients over a more extended period, while fast-release granules offer immediate nourishment.

Mobility of Nutrients

Nitrogen and potassium, two essential elements in fertilizers, are mobile in the soil. This means they can easily move and be absorbed by plant roots. However, phosphorus, the third crucial element, is immobile in the soil. Granular fertilizers with phosphorus that is far from the roots may not be effectively absorbed. In contrast, liquid fertilizers offer uniform nutrient distribution throughout, ensuring plants receive both mobile and immobile nutrients.

Effects on Plant Health

Improper use of fertilizers can result in burned leaves due to the accumulation of salts in the soil. Plants regulate the salt content by expelling water from their leaves, disrupting the osmotic process responsible for nutrient absorption. To prevent leaf burn, it is crucial to water plants regularly and dilute liquid fertilizers before application. Granular fertilizers should be spread a few inches away from plant roots to avoid direct contact.

Further reading:  Secrets to Creating the Perfect Homemade Fertilizer for Your Flowering Plants

Effects on the Environment

Regular use of fertilizers can lead to nutrient enrichment in groundwater and bodies of water, a process known as eutrophication. Slow-release fertilizers are less damaging to the environment, while liquid fertilizers, being fully soluble, leach more easily during rainfall or watering. To mitigate these effects, it is essential to apply fertilizers conservatively and avoid fertilizing already nutrient-rich soil.

Correction of Nutrient Deficiencies

When plants lack specific nutrients, they exhibit symptoms such as chlorosis (loss of green pigmentation) or leaf curling. Liquid fertilizers are advantageous in correcting nutrient deficiencies due to their quick absorption by plant leaves. In contrast, granular fertilizers, particularly slow-release granules, take longer to be absorbed and utilized by plants.


Granular fertilizers are relatively easy to store since they are solid and dry. However, it’s important to keep them in a dry environment to prevent microbial growth. On the other hand, liquid fertilizers should be stored in air-tight containers, preferably in a dark room to prevent the growth of competing microorganisms. Light can disrupt the photosynthetic process within the container.

Apart from these differences, other factors such as equipment requirements and shelf life also vary between granular and liquid fertilizers.

Plants That Thrive With Different Fertilizer Types

While plants cannot distinguish between nutrients from granular or liquid fertilizers during absorption, different plants and growth phases may have varying preferences. Some plants that generally respond well to granular fertilizers include wheat, lettuce, light feeders, and slow-growing plants. On the other hand, corn, pepper, tomato, broccoli, cabbage, sunflower, strawberry, and heavy feeders tend to benefit from liquid fertilizers.

Further reading:  The Battle of Fertilizers: Liquid vs. Granular

Converting Granular Fertilizer into Liquid

If you already have granular fertilizer and prefer to use it in liquid form, there is a way to convert it. Here’s how:

  1. Soak the granules in distilled water for 24 hours, starting with a 1:1 ratio and adjusting as needed.
  2. Mix the solution thoroughly and filter out any undissolved solids.
  3. Don’t discard the undissolved solids; apply them to your garden.
  4. Store the liquid fertilizer in a container with a closed lid, in a dark room.

Remember to use pure water to prevent the growth of microorganisms that can compete with or harm your plants when the fertilizer is applied.

Applying Liquid Fertilizers

Liquid fertilizers can be applied through different methods, depending on your needs:

1. Direct Soil Application

You can apply liquid fertilizers directly to the soil. For daily applications, mix 1 part liquid fertilizer with 10 parts water.

2. Foliar Feeding

Foliar feeding is the quickest method to address nutrient deficiencies. Simply put some fertilizer, with a higher concentration of the lacking nutrient, into a spray bottle and apply it to the leaves.

3. Fertigation

Fertigation involves feeding and watering plants simultaneously using an irrigation system. Add some liquid fertilizer to your irrigation tank and water your plants daily. To prevent nutrient overload, mix 1 part fertilizer with 25 parts water.

In Conclusion

Fertilizers are essential for the healthy growth of plants, and they come in both granular and liquid forms. While granular fertilizers can be converted into liquid form, the choice between the two ultimately depends on personal preference, application methods, and the specific needs of different plants. Whether you opt for granular or liquid fertilizers, it’s crucial to consider the benefits and drawbacks of each and apply them conscientiously.

So, which type of fertilizer do you prefer? Share your thoughts in the comment section below.