How to Mix Granular Fertilizer Into Liquid: Complete Guide

Ever looked at that bag of granular fertilizer and wondered if you could turn it into a liquid solution? You’re not alone.

Here’s the deal: mixing granular fertilizer into liquid is totally doable. And it can save you money while giving your plants a faster nutrient boost than traditional dry applications.

I’ve been converting granular fertilizers into liquid solutions for years. And in this guide, as a professional fertilizer mixer machine manufacturer, I’ll show you exactly how to do it right.

how to mix granular fertilizer into liquid

Table of contents

Why Convert Granular Fertilizer to Liquid?

Before we dive into the how-to, let’s talk about why you’d want to make liquid fertilizer from granular in the first place.

Faster Nutrient Uptake

Liquid fertilizers are absorbed by plants way faster than granular ones.

Think about it:

When you apply granular fertilizer, it needs to break down in the soil first. Then it needs moisture to dissolve. Only then can plants absorb the nutrients.

But with liquid fertilizer? The nutrients are already dissolved and ready to go.

Better for Container Plants

Container plants LOVE liquid fertilizer.

Why?

Because the nutrients get distributed evenly throughout the pot. No hot spots. No nutrient pockets. Just consistent feeding throughout the root zone.

Works in Cold Weather

Here’s something most people don’t know:

Granular fertilizers barely work when soil temperatures drop below 50°F. The microbial activity that breaks down the fertilizer basically stops.

But liquid fertilizer? It works immediately, regardless of temperature.

Cost Savings

A bag of granular fertilizer costs way less than pre-made liquid fertilizer. By making your own liquid solution, you get the benefits of liquid fertilizer at granular prices.

Which Granular Fertilizers Work Best?

Not all granular fertilizers dissolve well in water.

Here’s what works:

Water-Soluble Fertilizers

Look for bags that specifically say “water-soluble” on the label. These dissolve completely with minimal residue.

Examples include:

Miracle-Gro Water Soluble All Purpose Plant Food
Jack’s Classic fertilizers
Most synthetic fertilizers (like 20-20-20 or 10-10-10)

What to Avoid

Stay away from these types:

Slow-release fertilizers (they have coatings that won’t dissolve)
Organic fertilizers with large chunks (like bone meal)
Time-release pellets
Fertilizers with polymer coatings

How to Mix Granular Fertilizer Into Liquid: Step-by-Step Instructions

Let’s get into the actual process.

What You’ll Need

Water-soluble granular fertilizer
Large bucket or container
Warm water (not hot)
Stirring stick or drill with mixing attachment
Fine mesh strainer or cheesecloth
Storage container

The Basic Recipe

The standard mixing ratio is 1 cup of granular fertilizer per 1 gallon of water.

But here’s the thing:

This ratio works for most general-purpose fertilizers. For high-nitrogen fertilizers, start with 3/4 cup per gallon to avoid burning your plants.

Step 1: Add Fertilizer to Container

Pour your measured fertilizer into the bucket first. Don’t add water yet.

Step 2: Add Warm Water

Now add warm water (around 80-90°F). Warm water helps the fertilizer dissolve faster than cold water.

Pro tip: Add the water slowly while stirring to prevent clumping.

Step 3: Mix Thoroughly

Stir the mixture well. Really get in there. I use a paint mixing attachment on my drill for larger batches.

Step 4: Let It Soak

This is the most important step that people skip:

Let the mixture sit for 24 hours.

Stir it occasionally during this time. This extended soak ensures all the nutrients dissolve properly.

Step 5: Strain the Solution

Even with water-soluble fertilizers, you’ll likely have some sediment.

Use a fine mesh strainer or cheesecloth to filter out any particles. This is crucial if you plan to use the liquid in a sprayer.

The leftover solids? Don’t toss them. They still have nutrients and work great as a light top dressing for garden beds.

Application Methods

Now that you’ve got your liquid fertilizer, here’s how to use it.

Foliar Feeding

Spray the diluted solution directly on leaves for the fastest absorption.

Important:

Dilute to 50% strength for foliar application
Apply early morning or evening to prevent leaf burn
Avoid spraying in direct sunlight

Soil Drench

Pour the liquid around the base of plants, ensuring it reaches the root zone.

This method works great for:

Vegetable gardens
Container plants
Newly transplanted seedlings

Through Irrigation Systems

Add the liquid fertilizer to your watering can or irrigation system for easy application.

Just be sure to:

Clean your equipment after use
Use well-strained solution to prevent clogs
Adjust concentration based on frequency of watering

Concentration Guidelines

Getting the concentration right is critical.

Here’s my tested approach:

For Different Plant Types

Seedlings and young plants: Use 1/2 the standard concentration

Established vegetables: Use full strength (1 cup per gallon recipe)

Flowering plants: Start with 3/4 strength and adjust based on response

Trees and shrubs: Use 2-3 gallons of full-strength solution per plant

Testing Your Mix

Before applying to your entire garden:

Test on a small area first
Wait 24-48 hours
Check for any signs of fertilizer burn
Adjust concentration if needed

Safety Considerations

Let’s talk safety for a minute.

Personal Protection

Always wear:

Gloves when handling concentrated solutions
Eye protection when mixing
Long sleeves to prevent skin contact

Storage Tips

Store your liquid fertilizer in:

Labeled containers (super important!)
Cool, dark places
Child-proof areas
Sealed containers to prevent evaporation

Environmental Concerns

Never:

Pour excess solution down storm drains
Apply before heavy rain
Over-fertilize near water sources

Troubleshooting Common Issues

Sometimes things don’t go as planned. Here’s how to fix common problems.

Fertilizer Won’t Dissolve Completely

This usually means:

You’re using the wrong type of fertilizer
Water is too cold
Not enough soaking time

Solution: Use warmer water and let it soak longer. If it still won’t dissolve after 48 hours, you probably have a slow-release formula.

Plants Show Burn Symptoms

If you see brown leaf edges or wilting:

Dilute your solution more
Flush soil with plain water
Reduce application frequency

Clogged Sprayer

To prevent clogs:

Always strain thoroughly
Use finer mesh filters
Clean equipment immediately after use

Advanced Mixing Techniques

Want to level up your liquid fertilizer game? Try these pro techniques.

Using Organic Granular Fertilizers

While trickier, you can make liquid solutions from organic fertilizers:

Use hot (not boiling) water
Soak for 48-72 hours
Strain multiple times
Expect more sediment

Creating Custom Blends

Mix different fertilizers for specific needs:

High nitrogen for leafy growth
Balanced for general feeding
High phosphorus for blooming

Just calculate each component separately, then combine.

Adding Supplements

Enhance your liquid fertilizer with:

Kelp extract for growth hormones
Epsom salt for magnesium
Calcium solutions for tomatoes

Money-Saving Tips

Let’s talk about maximizing your fertilizer budget.

Bulk Buying

Buy granular fertilizer in 50-pound bags for the best price per pound. Store properly and it’ll last years.

Batch Preparation

Make larger batches and store them. A 5-gallon batch usually lasts me 2-3 weeks.

Dilution Strategies

Remember: You can always dilute more, but you can’t make it stronger once mixed. Start with less fertilizer if you’re unsure.

The Bottom Line

Converting granular fertilizer to liquid gives you flexibility, faster results, and significant cost savings.

The key points to remember:

Use water-soluble fertilizers only
Follow the 1 cup per gallon ratio (adjust for high-nitrogen types)
Always soak for 24 hours
Strain before use
Test on a small area first

Once you master how to mix granular fertilizer into liquid, you’ll wonder why you didn’t start sooner. Your plants will thank you with faster growth, better yields, and healthier appearance.