Laura Walters
One of the latest plant hack buzzing around gardening circles is using rice water for plants. Many folks swear it’s a miracle boost for blooms and veggies. The starchy liquid from cooking rice supposedly feeds roots and keeps pests at bay. But is rice water good for plants or is it just kitchen waste you should pour down the drain? The answer is a bit murky, but I've dug into the details for you and will tell you whether this trick is worth trying.
DIY liquid fertilizers for plants are a smart way to nourish gardens without breaking the bank and rice water sounds like it could fit the bill. It’s cheap, easy, and uses what’s already in your kitchen. Giving plants pasta water is another common hack, with some claiming it’s a nutrient-packed alternative to traditional fertilizer.
I'll break down how using rice water for plants works, how you can try it at home, whether fermented rice water for plants is better, and how these methods stack up against the classic pasta water for plants trick. Let's take a look at how surprising fertilizers you can find in your kitchen really hold up and if they're worth your time.
What Is Rice Water?
Before boiling rice, you're supposed to rinse it to wash away any dirt, debris, pesticides, and even pests (yuck!) leftover from the harvesting and hulling process. When you rinse your rice, there's cloudy leftover water that holds starches and trace minerals that plants in your garden or houseplants collection can use. Instead of tossing it down the drain, put it to use for your plants.
This starch wakes up soil microbes, which turn it into food for roots. It’s more of a slow-release snack and less like a full-blown, balanced fertilizer. Rice water is not a cure-all either. Overuse can attract pests or mold, especially in wet climates.
Fermented rice water for plants also adds probiotics, like lactic acid bacteria and Bacillus cereus, which boost soil health. Though watering plants with plain boiled water works fine, it won't have the additional starch to feed microbes.
Leftover pasta water carries wheat starches that act in a similar way to rice water. Both are safe and cheap, but neither replaces fertilizing houseplants with a balanced fertilizer like this one from Miracle-Gro on Amazon.
Benefits of Rice Water for Plants
Tomatoes respond especially well to starchy rice water. The starch fuels soil microbes that help roots soak up water by loosening the soil, especially when fruits are forming. Peppers may pop out more buds with regular doses of rice water, too.
Acid-loving plants like blueberries or azaleas, however, prefer pasta cooking water. Its slight acidity matches their soil needs. What other plants like pasta water? Rhododendrons and hydrangeas dig it, too.
Houseplants like pothos or peace lilies take to rice water like champs. It keeps their soil moist without overloading nutrients. Skip this trick for succulents, though—they hate the extra wet.
Potential Risks of Rice Water
Since leftover pasta liquid carries starch from wheat, which makes it a touch acidic, it works as a mild fertilizer for certain plants but not for others. For plants that prefer alkaline soil, avoid adding pasta water.
And though the carbs in pasta water and rice water both feed soil microbes, on their own, neither method can carry a garden. Pasta water has fewer vitamins than rice water, so it’s less nutrient-rich. Too much can also pull in ants or slugs. Dilute it and use sparingly.
Make sure to only use unsalted pasta and rice water, because salt can negatively impact plants. Pasta water is a decent homemade plant food, but rice water wins for most gardens. A meter for testing, like this one from Amazon, can help you to determine whether it is making a difference or not.
How to Use Rice Water for Plants
Making rice water for plants is a breeze. Before boiling rice next time you make dinner, rinse your rice in the water, mixing it with a spoon. Once the water becomes cloudy, pour it off into another container or use a strainer or slotted spoon to remove the rice, then cover the rice in another batch of water, and repeat the process. Do this two or three times or until the rice water looks less murky and mostly clear (it won't be perfectly clear).
Next mix 1 part rice water with 5 parts fresh water so it doesn’t cause fertilizer burn. Use it weekly on houseplants or garden beds.
Fermented rice water for plants is another good option for homemade plant food. Take your rice water and let the strained liquid sit in a jar for 3-5 days at room temperature until it smells tangy. Dilute 1:10 with water and use every two weeks. A spray bottle is great for misting leaves.
I toss in a pinch of Epsom salt for a magnesium boost—it’s not required, but gives plants a little extra boost. You find Epsom salt on Amazon for just a few bucks. Keep leftover rice water in the fridge for up to a week.
How Other Alternatives Compare
Pasta water is mostly starch. That cloudiness you see after draining noodles feeds soil microbes and can give a little lift to plants that like a touch of acidity. But again, steer clear of salted water—it will fry roots instead of feeding them. Dilute your pasta water and think of it as a light snack for plants.
Cooked vegetable water has more going for it. When you boil potatoes, carrots, or green beans, minerals and vitamins leach into the pot of water. You can use these nutrients to give your garden an extra dose of goodness.
After boiling veggies, strain the cooking water, let it cool, and you’ve got a mild tonic that fruiting crops will appreciate. It’s still not a substitute for real fertilizer, but carries more nutritional variety than plain pasta water.
When comparing these viral plant hacks side by side: pasta water is simple starch with a slight acidic edge, while vegetable water offers a broader nutrient mix. Both are worth using, but veggie water tends to give plants more substance in the long run.
Cooking Water Plant Food Recipe
Try a kitchen waste fertilizer mix for plants. Boil potato peels or carrot tops in water for 20 minutes, strain, and dilute it in a 1:5 ration with fresh water. The peels supply quite a significant portion of potassium, which is great for fruiting crops. Also, I recommend tossing in a banana peel for even more potassium, plus a touch of phosphorus.
For an even better and more balanced food, it is a good idea to mix in crushed eggshells while the water boils to release calcium. Or you can add a spoonful of used coffee grounds for a light nitrogen boost. A few spinach stems or other leafy scraps also contribute to an extra kick of iron and magnesium.
Spray or soak soil weekly with one of these mixes. Use a watering can with a fine spout. This works best for even coverage and will prevent too much soil disturbance. Leafy greens will perk up from the added nitrogen. Fruiting crops will soak up the potassium. And calcium will protect tomatoes against blossom end rot.
These homemade mixes are safe, cheap, and surprisingly broad in nutrients. Just store leftovers in the fridge and use within a week so they don’t sour. Think of it as a gentle, all-around plant tonic made from scraps you’d normally toss.
But remember that rice, pasta, and veggie water won’t replace a good compost tea. But they’re an easy way to turn kitchen waste into garden fuel faster. Pairing these DIY brews with a good organic liquid fertilizer, like this one from Amazon, will give your plants the full range of nutrients they need.
