Should I Use Coffee Grounds on My Dieffenbachia?

Coffee grounds are a great source of organic matter that is cost-effective and abundantly available. They are often used to fertilize acid-loving houseplants like Dieffenbachia in California.

Dieffenbachia, or dumb cane, prefers to grow in slightly acidic soil and likes coffee grounds. Coffee grounds also provide a good source of nitrogen while improving the soil’s pH balance. Excessive use of coffee grounds could harm Dieffenbachia. Let’s find out more.

Are Coffee Grounds Good for Dieffenbachia?

Live Dieffenbachia Camille 10 in. Grower's Pot | Indoor Dumb Cane Houseplants | 18in. Tall Easy Low Light Plant with Included Guide

The nutritional profile of coffee grounds makes them well-suited to Dieffenbachia. They can be beneficial to dumb cane plants in moderate doses.

However, it would be best to not rely on coffee grounds as a fertilizer for dumb canes. This is because if the soil has a high amount of nitrogen, the extra dose from coffee grounds could impede the growth of dumb cane.

With this disclaimer out of the way, coffee grounds can have undeniable benefits for acid-loving plants. It would be best if you used them in moderate amounts.

Also see: Are Dieffenbachia Toxic To Cats?

The Nutritional Benefits of Coffee Grounds for Dieffenbachia

Let’s review coffee grounds’ nutritional content to see why they are useful.


Coffee is rich in nitrogen and can significantly improve the growth rate of dumb canes. However, this only applies if your plants have a nitrogen deficiency.

Consider using coffee grounds if you want to boost your plant’s nitrogen content.


Calcium is a vital macronutrient for dumb cane plants. All plants need it in large quantities to form cell walls and cells. The right doses of calcium can help your plant overcome growth plateaus.


Potassium plays a useful role in photosynthesis, allowing Dieffenbachia to grow faster. It is associated with the movement of nutrients, carbohydrates, and water in plant tissue.

Note that coffee grounds only provide trace amounts of potassium. They can be used to supplement your Dieffenbachia and should not be a substitute for fertilizer.


Magnesium is the ‘powerhouse’ that drives photosynthesis in dumb cane plants. Plants with a magnesium deficiency will fail to harness energy from the sun for photosynthesis.

In other words, if you want your Dieffenbachia plants in California to look green and healthy, ensure they have a good quantity of magnesium.

Read here: Can You Grow Dieffenbachia From Cuttings?

What Type of Coffee Grounds Can I Use with Dieffenbachia?

Using plain coffee grounds or back coffee on your Dieffenbachia is recommended. In other words, it is not ideal for dumping your leftover coffee into the plant.

This is because your coffee leftovers may have added sweeteners. This can attract predatory insects such as ants that will attack your Dieffenbachia in California.

Depending on how you like your coffee, it may contain dairy content. Dairy should never be added to the soil of Dieffenbachia or any other plant.  

It becomes fertile ground for gnats and flies and creates a stressful environment for Dieffenbachia.

Dumping your leftover coffee may expose them to nasty bacteria that could lead to root rot and other diseases.

Should I apply Coffee Grounds Directly to the Soil?

Adding coffee grounds directly to dieffenbachia soil is not recommended because it can lead to several problems.

Coffee grounds can create a small layer over the soil that can prevent moisture from escaping the soil. This can waterlog the plant and create soggy soil.

Dieffenbachia in California does not prefer waterlogged conditions. It can create a stressful environment for your plants and lead to root rot.

In some cases, adding coffee grounds could also expose your Dieffenbachia to fungus infections and pest infestation.

If you’re not careful, adding coffee grounds could stunt Dieffenbachia’s growth instead of boosting it.

Moreover, coffee grounds are not meant to be used frequently. You should only use them sparingly to supplement any nutritional deficiencies in your Dieffenbachia.

Why Coffee Grounds Should Not be Used Frequently

You should never replace the usual fertilizer for Dieffenbachia with coffee grounds. This is because too much coffee ground will alter soil properties.

You could disrupt the balance of organic matter to inorganic matter. If the organic matter rises too much in the soil, it can retain more water.

This can make the soil soggy and waterlog the plant. This is the opposite of what dieffenbachia plants need.

Dieffenbachia plants in California require soil that retains enough water but also drains moisture at the same time.

And while Dieffenbachia prefers slightly acidic soil, too much coffee ground can make the soil extremely acidic.

This could impede growth and even burn your Dieffenbachia roots in California.

Never Use Coffee Grounds on Dieffenbachia Pups

It is not advisable to use coffee grounds on young dieffenbachia pups. Coffee grounds could stunt the growth of young plants.

Don’t use coffee grounds on your Dieffenbachia plants while they are still young. Allow the plants to mature before introducing them to coffee grounds.

Dieffenbachia Compacta (Tropical Snow) - 8'' from California Tropicals

Pest Infestation with Coffee Grounds

Using coffee grounds too frequently will create the perfect conditions for pests. This is because coffee grounds make the soil soggy.

Most bugs prefer a moist environment. This is why too many coffee grounds create the ideal conditions

Unsightly pests such as gnats, aphids, and mealybugs may soon call your dieffenbachia plants home. Some pests, such as aphids, can deplete root systems by eating their roots.

This will eventually make your dieffenbachia plant weak and stop its growth. There’s a way of using coffee grounds without the risk of inviting pests.

Use coffee grounds as a liquid fertilizer. This will allow your dieffenbachia plants to extract the benefits of coffee grounds without being exposed to pests.

The Risk of Fungal Infections

Using coffee grounds may increase the risk of fungal infections in your dieffenbachia plants. This is because coffee grounds take a long time to break down for the plant to use its nutrients.

Meanwhile, they might invite fungi that will infect your dieffenbachia plants. In some cases of fungal infections, your dieffenbachia plant may die – and you won’t know until it’s too late.

This is why it is better to use coffee grounds as liquid fertilizer.

How to Use Coffee Grounds on Dieffenbachia?

You now know the risks of using coffee grounds on Dieffenbachia. Still want to use coffee grounds on your Dieffenbachia?

There are safer alternatives to using coffee grounds instead of adding them directly to your Dieffenbachia.

Here’s  how you can safely use coffee grounds with Dieffenbachia:

  • Liquid fertilizer
  • Mulch
  • Compost

Liquid Fertilizer (or Fertilizer ‘Tea”)

Using coffee grounds as a liquid fertilizer is safe for Dieffenbachia. Here are the steps you can follow to make liquid fertilizer from coffee grounds:

  • Add 2 cups of coffee grounds to 5 gallons of water
  • Allow the coffee grounds to steep in the water for a few hours
  • Use the mixture as a liquid fertilizer for your Dieffenbachia and other plants
  • You can spray the mixture directly on the leaves and stems.

You may use the liquid fertilizer once or twice every month. It will encourage your dieffenbachia plant to grow and provide all the benefits.


Coffee grounds are one of the easiest foods to compost. To make compost with the coffee ground, mix the used ground into your existing compost pile.

That’s it! There’s no need to turn the compost or make other changes to it. You can improve the compost by adding other items such as coffee filters.


Mulching is when you add another layer to the soul. Coffee grounds can be used as mulch. Simply mix the coffee grounds with various organic matter such as leaf and compost before using it as much.

However, try to use a small quantity of coffee grounds in the mulch. Adding too much may harm your Dieffenbachia by increasing their nitrogen dose and altering the soil’s pH level.

Can I Water My Dieffenbachia with Liquid Coffee?

It’s easy to use liquid coffee on Dieffenbachia. But this is not recommended because the cons outweigh the pros.

Instead, use coffee grounds in the form of liquid tea, compost, or mulch. If you water your Dieffenbachia with leftover coffee, you may overwater the plant or impede its growth.

If you’re still tempted to add liquid coffee to your plant, don’t add it when it’s hot. Extreme temperatures will be stressful for the plant.

Allow the coffee to cool to room temperature before introducing it to the plant.

Pro tip: Dilute the leftover coffee with water because concentrated amounts of coffee can burn the Dieffenbachia’s roots.

Where Can I Obtain Coffee Grounds From?

To possess coffee grounds, you don’t have to be an avid coffee drinker. You can always ask coffee houses near you to provide you with used coffee grounds.

Most of them will be happy to provide them to you for free. You might even be doing them a favor by taking the coffee grounds.

Wrapping Up

So there you have a detailed guide on using coffee grounds with Dieffenbachia.

Dieffenbachia plants do like coffee grounds – but in low to moderate doses. You should only use them occasionally to supplement with existing fertilizers. Have you ever used coffee grounds with dieffenbachia plants in California? Let us know how it worked out for your plants.

Also, you may like to read more articles: