Is Vermicompost Good for Hibiscus Plants?

Vermicompost is an excellent natural fertilizer that doubles as an environment-saving alternative to sending waste to the landfill. It can be used on many plants, from large trees to tiny carrots. So, can hibiscus plants benefit from the use of vermicompost?

Vermicompost is good for hibiscus plants in moderate amounts, but too much vermicompost can be toxic for hibiscus plants. You need to mix worm castings with regular soil to get the most benefit.

Vermicompost has so many benefits for hibiscus plants. In this article, we will discuss the wide range of beneficial nutrients vermicompost provides, as well as ways to use vermicompost effectively.

Benefits of Vermicompost for Hibiscus Plants

Vermicompost or worm manure is a rich fertilizer with many great benefits. When the worms process waste, many nutrients, and microbes are added that you cannot find in traditional dirt or soil. 

Vermicompost is beneficial to hibiscus and other tropical plants because it is a good source of nutrients. Some of the helpful nutrients in vermicompost are:

  • Nitrogen. Supports the production of protein and amino acids.
  • Potassium. Helps plants withstand high temperatures, which is particularly important for tropical plants like hibiscus.
  • Phosphorus. Helps build strong roots and prevent disease.
  • Magnesium. Essential to the intake of phosphorus and the production of chlorophyll, which gives plants a healthy green color. 
  • Calcium. Strengthens the structure of plants and controls the levels of acidity throughout the entire plant.
  • Sulfur. This is used to make protein and absorb many other nutrients.
  • Iron. Helps to create chlorophyll to sustain the health of the leaves on hibiscus plants.
  • Zinc helps plants to grow, reproduce, and hold water.
  • Copper. Helps prevent plant decay.
  • Boron. This is necessary for calcium usage and the pollination and reproduction of hibiscus plants.

All these nutrients in vermicompost help to keep hibiscus plants healthy and strong. When used to fertilize hibiscus plants, this increased fortitude results in:

  • More flowers: A study conducted by the American Society for Horticultural Science found that hibiscus grown in vermicompost produced 93% more flowers than those grown in traditional fertilizer.
  • Larger harvest: Similarly, food plants grown with vermicompost have been shown to produce more fruits and vegetables than those without it.
  • Brighter colors: Plants grown in vermicompost have been shown to produce brighter colored flowers.
  • Saves water: Worm castings retain moisture much better than traditional soil, reducing the frequency needed for watering.
  • Healthier plants: When mixed with soil, vermicompost helps kill bacteria that can harm plants. This results in less withering and death of plants.
  • Speeds up plant growth: Using vermicompost increases the growth hormones in plants. This causes plants to germinate faster and grow more quickly. Flowers can often be harvested sooner than those from plants without vermicompost.
  • Ideal soil texture: The texture of vermicompost is ideal for plant growth.
  • Effective seed-starter: Sometimes, soil can make it difficult for seeds to germinate because it can be pretty compact, and seeds are not strong enough to break through. Vermicompost is less dense than most soils, so it is more successful at sprouting new seeds.
  • Water absorption: Worm castings can hold a lot of water, which greatly benefits tropical plants that often have to withstand high temperatures.

Types of Vermicompost for Hibiscus

The waste used to make vermicompost can differ between bins. Some bins create worm castings from kitchen waste, while others use animal waste or a combination of the two.

While you cannot use vermicompost made from animal waste in as many ways as kitchen waste castings, both types of vermicompost are safe to use with hibiscus plants – as long as the hibiscus plants are not next to any food plants. 

You should only use vermicompost from kitchen waste if it is next to plants that will produce a given type of food (for people or animals).

How To Use Vermicompost for Flowering Plants

Vermicompost is packed with nutrients, which can be excellent for your plants. However, too many nutrients can be toxic. Therefore, you cannot use pure vermicompost for plants. Instead, use worm castings as the top layer on your soil or directly mix it with the soil.

You can either add the castings at the very beginning to germinate the seeds or add them to an already sprouted plant.

As Seed-Starter

If you are growing your hibiscus from seeds and prefer to sprout them inside before planting, you can add vermicompost to your soil. To do this, you should mix your worm castings into the soil before adding the seeds. Only use a small amount of castings in your seed starter, not more than a tablespoon.

As Top Layer

Adding worm castings as a top layer is one way to use them for fertilizer. Add an inch (2.54cm) of vermicompost to your soil for hibiscus plants planted outdoors. You can add more every two weeks at the earliest.

If you are growing your hibiscus in a pot indoors, add ¼ to ½ inch (¾ to 1 ¼ cm) of vermicompost to the top of the potting soil. Add a tablespoon every 15 days for every 6 inches (15 ¼ cm) of pot diameter.

Mixed in Soil

While we know that 100% vermicompost is not suitable for plants, there is a wide range of opinions on the proper ratio of potting soil to vermicompost

The most common ratio is 33%, or two parts potting soil to one part vermicompost, but some gardeners use a 1:1 ratio.

A study in the scientific journal Bioresearch Technology found that the ideal ratio is 40%, or two parts vermicompost to three parts soil. Adding more than 40% vermicompost did not increase the nutritional value for the plant. 

The most important consideration is the nutritional content of the dirt or soil you are adding the worm castings into. If it is very high in nutrients, you should add less vermicompost. However, if your soil does not offer many nutrients, your plants will be able to tolerate a higher percentage of vermicompost.

You can also add cocopeat into the mix. If you want to learn more, you can check out my other article here: How To Use Vermicompost and Cocopeat at the Same Time.

As Worm Tea

Worm tea is made from soaking vermicompost in water to create a concentrated, nutrient-dense liquid fertilizer. The tea is often higher in microbes than solid worm castings. 

You can use a spray bottle or a watering can to dispense the tea. Some people also add it to a drip line, but a typical size batch makes 5 gallons (19 liters) of tea, which is often not enough for large fields. To increase the coverage of worm tea, you can mix it with water in a 50/50 ratio. 

Unlike the solid vermicompost, worm tea can be sprayed on the entire plant, including leaves and flowers, although you should not spray it directly on food. 

The tea can also be used for transplanting flowers. You can spray the bare roots with the tea to help prevent transplant shock or problems commonly associated with moving a plant.

Worm tea has a lot of nutrients in it, so you should not use it at the same time as solid vermicompost. Using worm tea and solid worm castings a few weeks apart is fine.

You can find more information on worm tea in my other article: How to Make Vermicompost Tea (Ultimate Guide)

Other Tropical Plants That Benefit From Vermicompost

In addition to hibiscus, vermicompost is excellent for tropical plants. Tropical plants are often known for their bright flowers, and vermicompost can help increase the vibrancy of flowers.

Tropical plants are grown in hot areas and need lots of direct sunlight. The water retention of vermicompost is good for meeting their hydration needs.

Other tropical plants that benefit from vermicompost include, but are not limited to:

  • Lily
  • Bird of paradise
  • Orchid
  • Jasmine
  • Bougainvillea
  • Canna

Final Thoughts

While you cannot use pure vermicompost on hibiscus plants, you can use it in combination with soil or as worm tea. It is an excellent source of nutrients when used as a seed starter, top layer, or mixed in soil.

When determining how much vermicompost to add to your hibiscus plants, you want to consider the nutrients already provided by the soil you are using. Remember that too many nutrients can be harmful to hibiscus plants, so finding a balance is essential.

Happy vermicomposting!

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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