Are Coffee Grounds Good for Hibiscus – How to Use?

You can freely get used coffee grounds from shops, but is it worthy to be used on hibiscus plant? Some gardeners suggest it is useless to add this kitchen leftover to plants.

However, there are few studies that claim nitrogen percentage in coffee grounds can enrich the soil.

Before proceeding, let me answer this often asked question can I use coffee grounds to fertilize hibiscus plant?

Coffee grounds include nitrogen, phosphorus and potassium along with other minerals. But, these nutrients aren’t readily available for the plant to be absorbed. They need to be decomposed.

Composting used coffee grounds is the best way to reap its nutrients and enrich your hibiscus plant. It may take few months to break down its compounds to be make nutrients available for plants.

Not just composting, you can use coffee grounds as mulching agent, but you should use it in a proper way.

Apart from benefits, coffee grounds can also harm your plants. In this write-up I’ll uncover myths and facts of using coffee grounds for hibiscus plant.

What Nutrients Does Hibiscus Plant Need to Grow?

If you’re growing hibiscus in pots, then you should be aware that regular watering reduces nutrients in the potting soil.

Hibiscus plants that are grown in ground too need fertilizers to produce huge and vivid colored flowers.

Low levels of nutrients can be the reason why your hibiscus plant is not flowering.

Hibiscus plants love to be fertilized regularly slow-releasing fertilizers. You can use balanced liquid fertilizers to enrich the growing soil or add slow releasing organic fertilizers to strengthen the plant.

  • This flowering plant needs nitrogen which helps in leaf and stem growth, as well as chlorophyll production for photosynthesis.
  • Phosphorus in the fertilizer promotes root development, flower production and overall plant growth.
  • Potassium is essential for flower development and to develop resistance towards plant stress.
  • Other micronutrients such as iron, magnesium, calcium, zinc, manganese, and copper ensure enzyme functioning, chlorophyll production, and plant cell wall development.

In simple words, hibiscus plant need 10-10-10 or 20-20-20 balanced fertilizer.

Benefits of Coffee Grounds for Plants

Oregon State University states that adding coffee grounds to your compost will add-up 2 percent of nitrogen content to the compost.

It is to be noted that coffee grounds has 2 percent of nitrogen and 0.3 percent of phosphorus and potassium content in it.

So, instead of throwing left-over coffee grounds you can actually compost it as a green material. Composting worms like coffee grounds and decomposition process breaks them into essential nutrients.

Though compared to organic fertilizers, coffee grounds may not contribute much to your flowering plant. But, when you’re getting for free from kitchen why you should dispose them.

Note: While adding coffee grounds to compost pile, don’t excess more than 20 percent of the total volume of your compost. Also, you can add it to worm castings, but use in very small quantity.

Are Coffee Grounds Good for Hibiscus Plant?

are coffee grounds good for hibiscus plant

There are different opinions on the use of coffee grounds for plants. After reading them and going through study reports by State Universities, I conclude that it is safe to use coffee grounds on plants including hibiscus.

But, you should be able to wipe-off few myths around this kitchen leftover, which I will discuss later in this article.

  • University of Arizona states that you can nitrogen rich content composed coffee grounds are good for plants.
  • Oregano State University carried a study which concludes adding coffee grounds can gift your compost with nitrogen.
  • says that composed coffee grounds can acts as organic matter for your potting soil.

Let me also share one more article link that doesn’t recommend use of coffee grounds. Now, I’ll leave up-to you. Before that I ensure you read below points.

  • Using coffee grounds as mulch can block aeration and make it difficult for plants.
  • You shouldn’t use hot or fresh coffee grounds directly on hibiscus plants.
  • Though coffee grounds are known to make the soil acidic, composed coffee ground is mildly acidic and it is not constant.
  • Study show when coffee grounds are used as mulch to germinate seeds, it had negative impact. So, avoid using pure coffee grounds for seed germination.

( Also Read: Is Bone Meal Good for Hibiscus Plants?)

How to Use Coffee Grounds for Hibiscus Plant?

Fertilizing or gardening on the whole is easy when done correctly. A small mistake can negatively impact overall growth of the plant.

After reading about nutrients in coffee grounds, I think there will be any gardener left who would like to throw this kitchen leftover.

There are different ways of using coffee grounds to your garden. I already discussed the most popular way in this article, composting.

Remaining ways are:

  1. Adding coffee grounds to compost
  2. Mix organic mulch with coffee grounds to be used as mulching agent.
  3. Liquid fertilizer.

Composting Coffee Grounds

You can compost coffee grounds in a large ground of compost pile, in a container or tumbler compost.

Though have nitrogen and other nutrients in them, they can readily benefit hibiscus plant until they are decomposed.

Dr.Chalker Scott shares that you should add not more than 20 percent of total compost.

This allows the growth of microorganisms that take the work of decomposing coffee grounds.

  • Add cooled used coffee grounds to your compost pile.
  • Though the color is brown, it adds up green material in the compost.
  • Accordingly, add brown material to the composting bin.
  • Mix thoroughly and leave for few months to be decomposed.
  • In confined areas, use of coffee grounds in worm castings proven to kill some earth worms. So, I don’t recommend use of coffee grounds for vermicomposting.
  • Composed coffee grounds add up organic matter that improves water retention and drainage ability of your soil.

Using Coffee Ground as Mulch

Avoid just sprinkling pure coffee grounds over the surface of the hibiscus plant.

Compact nature of this kitchen leftover can act as barrier and reduces air circulation.

However, when mixed with organic mulch in small quantity you can use it as mulching agent.

A report states that when coffee grounds are used as mulch to germinate seeds, it showed negative impact.

To avoid such issues, use coffee ground mulch for adult plants. Also, coffee ground mulch should be thin layered with 4 inched layer of organic mulch.

Liquid Fertilizing

To make liquid fertilizer out of used coffee grounds, you should boil them in water and allow them to cool.

Strain coffee grounds and collect liquid in a container.

This liquid contains nutrients that can enrich your plant.

Myths of Using Coffee Grounds for Plants

While there are confirmed advantages to using coffee grounds in compost, some claims made in online blogs about their benefits may turn out to be unfounded myths.

Adding coffee grounds won’t have any impact on the potting soil. Though it is mildly acidic, it isn’t stable.

Thus, if you read adding coffee ground can improve soil pH, then consider it as a myth.

This report clarifies that there is no scientific evidence to prove that adding coffee grounds can repel snails to keep pests away.

So, adding composed coffee grounds won’t help your plant to fight pests directly.

Don’t depend on coffee ground solely for your plant’s nutritional needs.

Though it has nitrogen, only 2 percent won’t be enough for hibiscus plant growth. Along with this kitchen leftover, you must use organic fertilizers to enrich growing soil.

Adding pure coffee grounds won’t help to improve soil structure.

You’re advised to mix organic material or compost along with decomposed coffee ground to improve soil texture.

As mentioned above, just spreading coffee grounds around the plant can make it difficult for plant to absorb nutrients and acts as barrier for soil aeration.

When to fertilizer hibiscus plants?

Hibiscus plants are heavy growers. It actively needs fertilizers to produce vibrant flowers and healthy foliage.

Depending on the growing stages of the hibiscus plant you should fertilize the plant.

  • Apart from adding compost while planting. You should add slow releasing fertilizers once the plant reaches certain height.
  • During growing season, along with slow releasing fertilizers use liquid fertilizers to promote healthy growth and blooming.
  • Early spring is the time to fertilize your hibiscus plant with liquid fertilizers.

Can adding coffee grounds make soil acidic?

Though there are claims that adding coffee grounds can make the soil acidic, researchers state that composed coffee grounds are mildly acidic and it is not stable. So, adding coffee ground won’t have any impact on your soil pH.

Hibiscus Plant Care Tips

Like most indoor plants, hibiscus plant doesn’t demand much attention. However, with little care you’re gifted with a bunch of vibrant blossoms.

It beautifies your gardening space and adds aesthetic appeal to it.

  • For its healthy foliage and vibrant flowers, hibiscus need adequate water, sufficient sunlight and slow releasing fertilizers.
  • With changing temperature and climate, you should regulate watering frequency of hibiscus plant.
  • Avoid overwatering, as it results in yellow hibiscus leaves and root rot.
  • Similarly, underwatered plant will have drooping leaves that affects blooming.
  • Give your hibiscus plant full sunlight. If the afternoon sun is intense in your region, then arrange partial shade with a cloth. Scorching sun often burn plant leaves.
  • Insufficient sunlight turn plant leaves discolored with stunted growth.
  • As already discussed about fertilizing, according to plant’s growth stage you should supply it with essential nutrients. If you fail to provide nutrients, then it won’t produce blossoms.
  • To encourage branching, you should prune plants.
  • Regularly inspect your hibiscus plant for pests like aphids, spider mites and white flies.


Adding coffee grounds may not show instant impact on your plant. But, nutrients in this kitchen leftover can contribute to hibiscus plant’s growth.

You should be aware of the safest way to use coffee grounds.

Adding coffee grounds to your composting pile is one of the most recommended ways. It ensures your compost pile has balanced nutrients to enrich your garden.

Though nitrogen, phosphorus and potassium are present in coffee grounds, they need to be decomposed to be readily available for plants.

After adding used coffee grounds to compost, microorganisms may take months to break its compounds.

Consider it as a green material and don’t use more than 20 percent of total volume of the compost.

You can also use it as mulch, but you should add organic mulch along with it.

Did you ever use coffee grounds to fertilize hibiscus plants? Let me know in comments.