The Benefits of Using Rice Water for Houseplants and Gardens

Rice water, the starchy liquid left over after rinsing or cooking rice, is gaining popularity as a natural fertilizer and growth stimulant for houseplants and gardens. While it may seem like an unconventional choice, rice water contains nutrients and compounds that can benefit plant health and development in numerous ways.

What is Rice Water?

Rice water refers to two types of starchy liquid:

  • Starchy rinse water: This is the milky water that results from rinsing uncooked rice. Rinsing helps remove excess starch and any debris from rice before cooking.
  • Leftover cooking water: After boiling or steaming rice, the leftover water contains many of rice’s nutrients and minerals that leached out during cooking.

Both types of rice water contain levels of carbohydrates, amino acids, vitamins, and minerals that make them useful additions to a plant’s soil or watering regimen. The composition can vary based on the type of rice and cooking method used.

Key Nutrients and Compounds in Rice Water

Rice water owes its benefits to the unique combination of compounds it contains:

  • Starch and simple sugars: Rice water contains high levels of starch and carbohydrates that plants can absorb for energy.
  • Amino acids: Essential amino acids like lysine, methionine, and tryptophan are present in rice water. Amino acids help build proteins needed for growth.
  • Cytokinins: These plant hormones stimulate cell division and growth. Cytokinins are found naturally in rice water.
  • Indoles: Indoles are metabolites that help promote plant health. They act as antioxidants and stimulants within plant tissues.
  • Minerals: Rice water contains mineral nutrients like potassium, manganese, and magnesium. These minerals serve various functions in plant growth and development.
  • Vitamins: B vitamins and antioxidants are present in rice water, helping plants synthesize proteins and boosting immunity.
  • Flavonoids: Compounds like flavones, flavonols, and anthocyanins have beneficial antioxidant and anti-inflammatory effects in plants.

Together, this unique nutritional profile makes rice water an excellent natural fertilizer and pest deterrent for plants.

Benefits of Using Rice Water in Gardens

Using rice water in your garden provides a wide range of advantages, from stimulating growth to increasing yield.

Promotes Faster Growth

The hormones, sugars, and minerals in rice water make it an excellent growth stimulant for nearly any plant. The cytokinins speed up cell division, while the amino acids are used to create new proteins needed for plant structure and function.

Faster cell growth and protein synthesis allow plants to grow bigger and stronger. Leaves, stems, roots, and flowers can all benefit from rice water’s growth-boosting effects.

Increases Fruit/Vegetable Yields

The nutrients and carbohydrates in rice water provide excellent fuel for developing fruits and vegetables. The extra energy allows plants to convert more sugars and nutrients into large, abundant produce.

Rice water is particularly helpful for increasing yields of fruiting plants like tomatoes, peppers, and squash. The minerals also help produce form strong structures to support heavy yields.

Deters Garden Pests

Rice water contains compounds that can act as natural pest deterrents for common garden critters. The flavonoids and antioxidants have anti-inflammatory properties that can discourage pests like insects and small animals from nibbling on leaves and vegetables.

Applying rice water topically can help form a protective barrier on plant surfaces. The indoles also stimulate plant immune responses against foreign invaders.

Improves Soil Nutrients

Using rice water helps introduce an influx of nutrients into garden beds and potting soil that plants depend on. The carbohydrates feed beneficial soil microbes like fungi and bacteria. These microorganisms break down organic matter into accessible nutrients for plant roots.

Over time, routinely adding rice water improves overall soil health and nutrient bioavailability. Plants can absorb more of the elements they need from fertilized soil.

Environmentally Friendly Alternative

Rice water is a renewable, natural alternative to synthetic fertilizers and pesticides. It avoids introducing harsh chemicals into gardens and local ecosystems. The nutrients are readily biodegradable as well.

Using what would otherwise be discarded rice water is also a sustainable way to reduce food waste. Rice water puts this nutritional byproduct to good use through plant nourishment.

Best Practices for Using Rice Water on Plants

While rice water has multiple benefits, there are some best practices to follow when using it in your garden:

Use Fresh Rice Water

The nutrients in rice water begin to break down and dissipate over time. For best results, use rice water within 12-24 hours of preparation. Refrigerating can extend this window to 3-4 days.

Fresh rice water has the highest levels of minerals, vitamins, and growth hormones that provide the biggest boost. Avoid using old, spoiled rice water.

Apply in Moderate Amounts

Plants need a balanced diet, so overdoing it with rice water can lead to issues. Use rice water for no more than 25% of total watering needs. For outdoor gardens, apply rice water once every 2-3 weeks. Houseplants can be fertilized 1-2 times per month.

Alternate rice water with regular watering to avoid excessive starch and carbohydrate levels. Monitor plants closely when first using rice water.

Add in Small Doses for Seedlings

Young sprouts and seedlings may be more sensitive to rice water’s effects. Use very diluted rice water for the first few weeks until plants are more established. Start with a 1:8 rice water to water ratio and slowly increase strength as the plants mature.

Too much too soon can overstimulate tender young plant cells. Build up rice water levels gradually for seedlings.

Use Both Rinse and Cook Water

Cooking rice concentrates more starch and minerals in the water, creating an even stronger fertilizer. But rinse water still provides benefits and avoids wasting the starchy runoff.

Alternate between using rinse and cooked rice water to take advantage of both. Cooked rice water may need further dilution.

Pair with Compost Tea

For an added boost, combine diluted rice water with compost tea. The nutrients in rice water help feed the microbes present in compost tea. This mixture provides a wide spectrum of minerals along with beneficial organisms.

Use a 1:1 ratio of compost tea to rice water so the starches do not overwhelm the compost’s living components.

Best Plants for Using Rice Water

Rice water can benefit almost any edible or ornamental plant. But some types of plants respond particularly well to rice water fertilization:

Leafy Greens

Lettuces, spinach, kale, chard, and other leafy greens thrive with rice water. The cytokinins spur rapid leaf and stem cell growth for faster yields of edible greens. The minerals also help produce nutrient-dense leaves.

Root Vegetables

Starchy rice water is an excellent fuel source for root crops like radishes, beets, turnips, onions, carrots, and potatoes. It stimulates enlarged roots, bulbs, and tubers. The minerals also boost the nutrient content.

Fruiting Plants

Tomatoes, peppers, eggplants, cucumbers, beans, peas, and squash all benefit from rice water’s ability to increase fruit set and yields. The carbohydrates provide energy for developing fruits while minerals improve quality.


Applying diluted rice water to herbs like basil, parsley, cilantro, oregano, and mint accelerates growth for frequent harvests. The flavonoids also enhance the concentration and potency of herbs’ essential oils.


Rice water can help ornamental plants like roses, dahlias, and marigolds achieve vibrant colors and prolific blooms. It fuels rapid flowering and flower production. The indoles also help plants form sturdy stem structures.


Indoor plants like philodendrons, ferns, orchids, succulents, and palms thrive with regular rice water feeding. The nutrients stimulate healthy foliage and support plants adapting to indoor environments.

Making and Storing Rice Water

It only takes a few simple steps to put leftover rice water to use in your garden:

Cooking Rice Water

  1. Rinse uncooked rice thoroughly until the water runs mostly clear. This removes surface dust and excess starches.
  2. Cook the rice using whatever amount of water is needed, according to package directions. Do not salt the water.
  3. After cooking, drain off the rice water into a storage container, being careful not to pour out the rice as well. Allow to fully cool.
  4. Dilute the cooked rice water with an equal amount of fresh water. The cooked water is highly concentrated and needs to be cut with plain water.
  5. Use the diluted rice water within 1-4 days. Freeze for longer storage.

Rinsing Rice Water

  1. Place uncooked rice in a large bowl and cover with cool water. Swirl the rice using your hand.
  2. Drain off the water once it becomes cloudy and starchy. Repeat 2-3 more times until the rinse water runs clear.
  3. Collect the starchy rinse water in a container. Use within 1-2 days.
  4. Dilute rice rinse water using a 1:4 rice water to fresh water ratio before using in the garden.

Storing Rice Water

  • Keep rice water refrigerated in a sealed jar or bottle to preserve nutrients. Use within 3-4 days.
  • For longer storage, pour rice water into ice cube trays. Freeze, then transfer frozen cubes to a bag. Melt what you need as needed.
  • Rice water can also be frozen in larger batches. Thaw in the refrigerator before using.

By following a few simple preparations, leftover rice water becomes a potent fertilizer full of growth-boosting properties ready to nourish your garden.

Rice Water Fertilizing Guidelines

Follow these tips when adding rice water to your garden or houseplants:

  • For new plants or transplants, use 1 part rice water to 8 parts water the first 1-2 times. Slowly increase strength over time.
  • Mature outdoor plants can handle 1 part rice water to 3 parts water, applied every 2-3 weeks.
  • Houseplants should be fertilized with a 1:4 rice water to water solution 1-2 times per month.
  • Spray rice water directly onto plant leaves and stems to deter pests. Start with a 1:8 dilution and increase from there if needed. Reapply after rain.
  • Water seedlings and sprouts with very diluted rice water (1:16) in the first few weeks to avoid burning tender roots and leaves.
  • Test rice water on a few leaves first to check for any adverse reaction before wide-scale use.
  • Always use fresh rice water and dilute as directed. Overly concentrated or old rice water can harm plants.

With proper dilution and application methods, rice water fertilizer can be worked into any gardening routine to harness its growth benefits. Adjust frequency and strength as needed based on specific plants’ needs.

Common Questions About Using Rice Water on Plants

Many gardeners new to using rice water have some common questions. Here are answers to some frequently asked questions:

Does it matter what type of rice I use?

The rice variety impacts nutrient levels, but any type works. Short grain brown rice contains the highest amounts. Avoid instant or enriched white rice.

What’s the difference between rinsed and cooked rice water?

Cooked rice water is more concentrated and potent since nutrients and starches leach into the water during boiling/steaming. Rinsing water is milder but still beneficial.

Can I use leftover rice instead of just the water?

Old cooked rice can harbor bacteria that could harm plants. Just the water is safest. Use fresh rice to make each batch.

Is rice water safe for all plants?

Most plants tolerate rice water well in moderation. Start with diluted amounts first. Avoid using on new transplants and seedlings until established.

Should I only use rice water, or combine it with fertilizer?

Rice water complements your normal fertilizer regimen. Use it in between regular feeding to boost nutrition and growth. Don’t completely replace fertilizer with rice water.

Can too much rice water burn my plants?

Yes, excessive amounts of rice water can overfeed plants and cause dry, damaged leaves. Stick to the recommended dilutions and frequency.

How long does rice water last?

For maximum nutrient content, use rice water within 24 hours. It lasts 3-4 days refrigerated. Frozen into cubes or batches, it lasts 4-6 months.

Rice water is generally safe when applied correctly. Monitor your plants closely and adjust as needed to avoid adverse effects.

Troubleshooting Rice Water Problems

Rice water is not without some potential downsides if used improperly. Here are some troubleshooting tips for common rice water issues:

Leaves look burned or damaged

Your rice water solution is too concentrated. Dilute more before using or apply less frequently. Always start more diluted for new plants.

Leaves or stems appear slimy

Too much uncooked rice starch without diluting is coating plant surfaces. Switch to cooked rice water and rinse plants after applying.

Soil appears moldy

Fresh rice water can spoil and grow mold if left unrefrigerated too long. Use promptly or freeze for later.

Plant growth seems stunted

Very old rice water loses its nutrients. Use fresh batches made every 1-2 weeks for best results.

Pests are still persistent

Increase rice water concentration for pest sprays or spray more frequently. Combine with other deterrents like neem oil for severe issues.

Plants decline or underperform

Avoid overusing rice water, especially with young or sensitive plants. Stick to the 25% or less rule for water needs.

Unlocking the Power of Rice Water for Stronger, More Productive Plants

Rice water’s unique nutritional profile makes it a prized supplement for gardens and houseplants. The trace minerals, carbohydrates, and potent plant hormones provide an accessible natural growth stimulant for nearly any variety. When used properly, rice water boosts yields, deters pests, and improves soil health through its bioactive compounds and nutrients. Harnessing this free byproduct of rice is an easy, sustainable way to take your cultivation to the next level. With the proper best practices, rice water can help your plants thrive and reach their full potential.