Skip to Content

Can You Use Fungicide And Fertilizer At The Same Time?

Every plant owner desires to provide the utmost care to their plant family. Fertilization is an important part of plant care, but if you also have to use fungicides on your plants, you might want to know if you can use both simultaneously.

You can use a fungicide with the fertilizer if the fungicide requires water for activation. Mix the fungicide and fertilizer in a spreader and apply them to your garden. However, do not use liquid fungicides with your fertilizer. Hold fertilization for 3-4 days before and after applying fungicides.

If you are here to know if you can use fertilizers and fungicides together at the same time, keep reading, as I will discuss this in detail.

fertilizer 4

I have done my best to address all of your concerns in the article below. However, if you still have any questions or are confused about the article, you can receive personalized one-on-one assistance from me by leaving a comment below. I will respond to your comment within a few hours.


Please note: Simplify Plants is reader-supported. Some links in the post are affiliate links and I get a commission from purchases made through links in the post.

Which fertilizer should never be mixed with fungicide?

To understand this, we must first know about those fungicides that should never be applied along with fertilizers.

This makes it easier to select fertilizers.

Compositions of fertilizers and fungicides are not very similar, but there are a few cases where we need to be selective while applying such chemicals.

Never mix liquid fungicides with fertilizers.

If the fungicide is liquid, try to apply it at least 3-4 days after or before applying fertilizer, as these fungicides do not need water.

Watering is essential after applying fertilizers as it allows the product to seep into the soil and get evenly distributed there, making it easy for the plants to absorb the micronutrients.

Moreover, letting fertilizers sit for too long on the plant surface or over the grass by skipping proper watering increases the risk of burning out the foliage.

Thus watering after fertilizing is beneficial.

If liquid fungicides are applied during this process, excess chemical dilution occurs, making the product less effective.

Moreover, watering during fertilizing causes the leaching of liquid fungicide particles deep into the soil, disrupting its functionality.

Watering may also cause runoff of the liquid chemical, which can lead to soil intoxication, hampering the growth of nearby plants that do not need fungicides.

The use of liquid copper fungicide along with any manure is never recommended.

It is essential to leave this fungicide completely in dried condition for at least 12 hours following its application.

Its composition does not allow you to use it with a chemical fertilizer that requires watering.

It is advised to use the fungicide before applying the fertilizer after maintaining a gap of at least three days in between. 

Let us go deep into some more information to understand this better.

Can foliar fertilizer be mixed with fungicide?

Fertilizing indoor plant

Foliar fertilizers are made of a specific group of chemicals that are mainly applied to the foliage of plants.

Manufactured by many commercial companies, these fertilizers can be organic, mostly used for food crops, or synthetic inorganic form designed for ornamental foliage plants.

Now the question arises whether they can be applied with fungicide or not.

Combined application of fungicide with foliar fertilizer reduces functional costs.

It is found that the combined application of these two products improves nutrient absorption and disease suppression.

It even has a positive impact on managing crop production rates in any seasonal or environmental condition. 

When fertilizer and liquid fungicide mix is a big no for plants, another important question arises with liquid fertilizers.

Gardeners often ask if they can mix fungicides with liquid fertilizers.

No such huge implication can be caused by using them together.

However, suppose a gardener uses a fertilizer that requires dilution or needs to be watered after application.

In that case, there is a major chance of fungicide wastage as it can rinse off the chemicals easily from its functional spot.

So it may act counterproductive.

The best way to deal with it is to opt for a granular fungicide that can be used with liquid fertilizer

Fungicide before or after fertilizer?

Liquid fertilizer mix

After researching all the does and don’ts, when you finally select an accurate fungicide for your plant that goes well even with the preferred fertilizer, even then you need to stop and think about the right time for its application.

Whether it should go before or after manuring is a tough choice.

  • In the case of granular fungicide, fertilizer can be applied at the same time. For liquid fungicide, maintain a 3-4 days gap before spreading fertilizer in your garden. This way, no interference in the fungicide function will be caused due to watering.
  • Maintaining a short interval between the application of fungicide and fertilizer is always beneficial, as this allows you to observe the impact of these chemicals on the plant.
  • The gap of 3-4 days supports the plant’s adaptation to those chemicals, too, as overburden with inorganic compounds can cause chemical toxicity.

We have already discussed the consequences of using fungicide and fertilizer mix.

You must thoroughly read the next part to determine which micronutrients are suitable for your plants.

Can micronutrients be mixed with fungicides?

Pothos nutrients

Micronutrients are trace elements found in plant tissue and are essential for the metabolic activity of plant cells.

Some of these essential elements are Zinc (Zn), Iron (Fe), Copper (Cu), Manganese(Mn), etc.

The word trace is important as it indicates that micronutrients, although essential, must be present in an accurately small amount in cells.

An excess of these elements leads to toxicity.

Fungicides are synthetic components that contain various chemical compounds of many elements.

For example, copper fungicides like Champ and Kocide contain copper hydroxide as their active component.

Maneb is formulated using 16.5% of manganese.

Many such other products are available commercially.

These components are useful in both ways, as besides preventing fungus infection, they provide nutrients to the plant.

But one must have proper knowledge of plant needs before selecting these components and using them with any micronutrients.

And for this:

  • Soil testing is important to know the deficiency of nutrients in the soil and to choose micronutrients accordingly.
  • To avoid toxicity, gardeners must understand the fungicide’s composition before blending it with any micronutrients.
  • After applying Zinc fungicidal spray, a proper tissue test must be done to check for the plant’s Zinc sufficiency. Only some Zn-based fungicides get readily absorbed by the soil.
  • For any unknown formulation of manganese and copper, it should not always be assumed that these fungicides will provide nutrients. As in many cases, these components remain in a form that is not easily absorbable by the plant. Additional micronutrient support is needed in such cases. Go for a plant tissue test to know whether the plant needs micronutrients. 
  • Copper fungicides tend to interfere with the function of some micronutrients like Zinc, Manganese by suppressing their absorption. After applying such a mix, proper monitoring is needed to check any signs of Mn-Zn deficiency in plants. 

Fungicides can not entirely fulfill micronutrient needs.

However, few fungicidal components can supply a moderate amount of plant nutrition. 

Factors like the pH of the soil and formulation of the chemicals can affect its function.

Tips to keep in mind while applying fungicides and fertilizers separately or as a mix

Scotts DiseaseEx Lawn Fungicide - Fungus Control, Fast Acting, Treats up to 5,000 sq. ft., 10 lb.

Here are a few things that you should note:

  • Always ensure your plants are getting enough direct or diffused sunlight as per their need to eradicate the possibility of fungal or pest infestation.
  • Slow-release fertilizer applied at proper intervals promotes growth, strength, and resistance to your plants.  
  • Besides applying fertilizers and fungicides, be accurate with other actions like aeration, mowing, pruning, watering, soil monitoring, and dethatching to make your plants more immune to any disease.
  • Never apply fertilizers on the foliage, as this obstructs the stomata and prevents gaseous exchange. 
  • Check the pH of the soil with a pH meter before applying any mix.
  • Use purified water after applying fertilizer or granular fungicides, as active agents in tap water can react with the chemical components.  
  • Often excess manuring leads to discoloration of the foliage and grass. Don’t confuse it with a fungal attack. If you are witnessing such an event after a few days of manuring, wait for some days to be assured about the exact cause. 

Final words

Whether you must mix fungicide and fertilizer while applying them to your plants can seem tricky. But, once you know what goes together and what doesn’t, you will not have any problem deciding.

You can use fungicide and fertilizer together if the fungicide requires water for activation. Avoid mixing liquid fungicides with fertilizers. Wait 3-4 days before or after you decide to fertilize.

Along with applying fertilizers and fungicides, take care of your plants or lawn by providing proper sunlight, water, and other requirements.

What is the best time to apply fungicides?

The best time to apply fungicide is during the morning or night when the temperature is low. As the day proceeds, temperature increases, lowering the relative humidity of the air. This, in turn, provokes the fungicide to evaporate fast (fungicides are mostly volatile), thus reducing its effect.

Can you apply too much fungicide?

Excess chemical products are never suitable for nature or any natural object. Always refer to the provided instruction regarding the amount of fungicide and work accordingly. Excess application of fungicides can cause soil toxicity and burn foliage and lawn grass.

Does fertilizer make fungus worse?

Using fertilizer in the right amount with a proper interval between reapplication will not promote fungal growth, but both over-fertilization and under-fertilization can lead to fungus infections. 

How long does fungicide take to work?

This entirely depends on its type and composition. For example, contact fungicides remain on the surface of the foliage and do not penetrate. They take almost 3 to 8 days to be effective properly. These fungicides form a protected shield over the blade and prevent fungus from entering. Thus they must be applied before any infestation occurs. 


Reference: Fertilizer effects on weed growth, Weed ControlWeed Removal TimingAbrasive Weeding.


Recommended Garden Supplies

Are you looking for a readymade indoor plant soil mix that you can open and pour? Check out rePotme. They offer a wide range of readymade soil premixes for all your indoor plants.


Sharing is caring!

Leave a comment

Your email address will not be published. Required fields are marked *