Is Rice Water Good for Orchids? (Answered)

Washed rice water, which is usually drained, is filled with nitrogen, phosphorus and potassium that can significantly contribute to optimal growth of orchid plants.

Along with these essential nutrients, it also includes macro and micronutrients proven to improve plant growth and nutritional uptake.

In this write-up, we shall discuss the benefits of rice water for orchids.

The milky water you get after washing rice is touted as an orchid fertilizer. Rice water is full of starch processed into soluble sugars by plants. 

This readily available organic fertilizer is packed with essential nutrients and minerals that promote healthy growth, aid in root development, and increase plant disease resistance.

Before you enrich your orchid plants with rice water, let’s first understand this liquid fertilizer’s impact on pH and soil bacteria. There were instances where excess usage of nutrients without proper inspection can lead to over-fertilization.

Is Rice Water Good for Orchids?

Fermented rice water is said to include primary nutrients like nitrogen, phosphorus and potassium that encourage ideal growth of orchid plants.

rice water for orchids

Enriching your orchid with rice water saves you from buying synthetic fertilizers, which is an effective way to reuse kitchen waste.

Apart from being inexpensive, rice water is readily available every day.

The best part is that you can store it for future use.

Along with rice water, kitchen leftovers like banana peel, coffee grounds and pulverized egg shells can be added to the compost bin.

What Nutrients Does Rice Water Have for Plants?

Starch is the key ingredient that benefits soil bacteria, strengthening plant roots and increasing disease resistance ability.

Along with starches, rice water includes beneficial nutrients like nitrogen, phosphorus, and potassium, which every plant needs.

  • Carbohydrates provided by starches are stored by the plant’s cell membrane, which is used as energy.
  • Adding rice water benefits the growing medium by promoting beneficial bacteria and fungi.
  • Helpful bacteria feed on rice water to secrete enzymes that increase nutrients in the soil.
  • Apart from adding nutrients, microbial activity improves soil texture and improves the draining ability of the soil.

Note: However, excess use of starch can increase bad fungi that may result in root rotting.

NPK Value in Rice Water

Nitrogen, phosphorus and potassium are primary nutrients that contribute to rooting, leaf formation, stem development and blooming.

Research conducted by Hasanuddin University, Indonesia, states that rice water has 0.011 % nitrogen, 15.30 mgL-1 of phosphorus and 0.03me/mL of potassium. It also includes iron, manganese, and other nutrients needed for plant growth.

The NPK value may differ depending on several factors.

Once every 2 weeks, you can replace tap water with rice water. Along with water, it is known to provide nutrients, benefit bacteria, and improve the nutrient absorption ability of the plant.

Also Read: Where Should I Put My Orchid in My House?

Summarizing: Benefits of Rice Water for Orchid Plants

Scientific studies back the use of rice water for plants.

Nitrogen: It contributes to the stem and leaf development of orchid plants. Supplying adequate nitrogen will enhance a plant’s ability to produce energy through photosynthesis.

Phosphorus: It promotes stronger roots and flowering and improves the overall reproductive ability of orchids.

Potassium: It’s a crucial nutrient that helps uptake nutrients along with water. 

The nutritional requirement of orchids varies depending on the plant’s growth stage.

Gardening experts recommend applying balanced fertilizer for optimal growth of orchids.

  • Adding rice water to plants helps them to grow at a better rate.
  • Rice water includes starch that feeds helpful bacteria in the soil.
  • Besides being environmentally friendly, rice water is more economically feasible than synthetic fertilizers.
  • Research conducted by the Department of Biology, Hasanuddin University, Indonesia, shows that rice water includes nitrogen, phosphorus, potassium, and other nutrients like iron, manganese, and zinc.
  • Another research concludes that washed rice water has leached nutrients that stimulate the optimal growth of plants.
  • Spraying rice water on foliage can enhance its look, as leaves readily absorb the nutrients.
  • Using fermented rice water helps orchids to repel insects and pests. It is one of the organic methods to deter pests.

Nutritional Needs of Orchids

The nutritional requirement of orchids is similar to other plants.

It needs macro and micro-nutrients for optimal growth.

Macronutrients like carbon, oxygen, hydrogen, nitrogen, phosphorus, potassium, calcium, magnesium and sulfur.

Micronutrients include copper, boron, manganese, molybdenum, zinc, chloride and nickel. (Source)

The plant gets carbon, oxygen and hydrogen from water and air.

Other nutrients need to be included in fertilizers.

You might have seen NPK values listed on fertilizers; these are essential nutrients that contribute to leaf, blooming, and root growth.

Along with these essential nutrients, you must add calcium, magnesium, and fertilizers.

Fermented rice water has essential nutrients: calcium, iron, magnesium and sodium. (Source)

How to Use Rice Water for Orchids?

Two simple ways to use rice water to fertilize orchids include top-watering and bottom-watering.

  1. Collect rice-soaked or boiled water (cool it down to room temperature) in a water container.
  2. Water the orchid plants once in 2-3 weeks.
  3. Plant roots easily absorb water-soluble minerals and nutrients in fermented washed rice water.
  4. You can mist the leaves of indoor plants with rice water.

The second method is to collect rice water in a tray and place an orchid pot with drainage holes in it for 20 minutes.

Bottom watering ensures you’re not overwatering your orchids.

How Does Orchids Absorb Rice Water?

Orchids are habitats in places where it gets heavy rainfall but stops suddenly.

So, to compensate and survive when there is no rainfall, orchid roots preserve water, nutrients, and minerals.

Similarly, when you use fermented rice water for orchids, the starch or carbohydrates are stored in new roots and leaves.

During the natural process of water uptake, water-soluble nutrients in rice water are absorbed by orchid roots.

Note: Though rice water is packed with nutrients and starch that benefit orchids, it can’t replace balanced fertilizer.

Does Rice Water Contain Starch?

Yes, rice water has starch that plants and fungi in the soil will break down to some sugar.

The concentration of starch in the rice water depends on the type of rice and the soaking duration.

Some studies state plants with rice water have shown enhanced growth compared to other plants.

Pros and Cons of Using Rice Water to Fertilize Orchids

It is one of the organic and inexpensive ways to enrich your ornamental plants.

Starch in rice water is consumed by microorganisms that benefit the orchid plant.

It strengthens plant roots and improves plant’s diseases resistant ability.

Cons include:

  • Fermented rice water attracts spiders and ants that aren’t good for orchids.
  • Along with helpful bacteria, bad bacteria and fungi can feed on rice water.
  • NPK percentage in rice water isn’t sufficient for the ideal growth of orchid plants.

Which Is Best: Rice Water from Soaking Vs After Boiling?

Leftover water obtained after boiling rice is slightly more nutritious than washed rice water.

Heating rice in water leaches a greater percentage of nutrients and minerals from the rice.

Allow the boiled rice water to reach room temperature before enriching the orchids.

I prefer both ways.

Whenever I use washed rice water, I resist watering orchids.

How long should I wait to water orchids after giving them rice water?

Insert your index finger into the potting soil. If you find the top 2 inches of the soil moist, then don’t water.

Water your orchids when you feel the top layer of the soil is dry.

If you’re using rice water, you can skip watering orchids that day.

Orchid Fertilizing Tips

Spring and summer are growing seasons of orchids. They must be fertilized with a balanced fertilizer to promote blooming and healthy plant growth.

With proper fertilization, your plant may produce enough blossoms and lack healthy foliage.

  • Don’t rely on rice water to fertilize orchids.
  • Along with rice water, you should apply NPK-rich organic fertilizer.
  • While using liquid fertilizer, follow the manufacturer’s instructions to dilute the solution.
  • Reduce fertilizing frequency during winter and fall, when the orchid goes dormant.
  • Water generously, as roots and water absorb nutrients in the soil.
  • To avoid salt build, flush potting soil with plain water.
  • Over-fertilization can stunt plant growth and reduce blooming, so follow the usage instructions labelled on the product.
  • Closely monitor the plant for signs of over-fertilization and nutritional deficiency.
  • Regulate fertilizing orchids according to the plant’s growth and climatic conditions in your region.

How Often Should I Apply Rice Water on Orchids?

Use rice water for orchid plants twice a month.

Ensure you also use a balanced organic fertilizer along with rice water.

Within a few months, you’ll see noticeable changes in your orchids.


Rice water has starch that can benefit good bacteria in the soil. It eventually impacts how efficiently the plant absorbs nutrients in the soil.

Feeding orchids with rice water is one of the inexpensive and organic ways to enrich the plant.

Along with minerals and nutrients, rice water can provide the required moisture to orchids.

Apply rice water twice or thrice a month.

Along with rice water, use NPK-rich organic fertilizer to encourage orchid blooming.

You must strike a balance by avoiding over-fertilization and supplying enough nutrients to plants.

Regularly monitor the plant for signs of nutrient deficiency and over-fertilization.