Can rice and pasta water feed your plants?

The short answer: yes — pasta water can be good for plants if it’s unsalted and cooled. The starchy water left over from cooking pasta or rice contains small amounts of nutrients that act as a gentle fertiliser. It’s a simple, zero-waste way to feed your garden, but only when used correctly.

We all want a healthier garden, but sometimes the best fertilisers aren’t found in a bottle. They’re in your kitchen sink, ready and waiting. That cloudy water left over from cooking rice, pasta, or even vegetables isn’t waste — it’s a gentle, free tonic your plants will thank you for.

Why pasta water is good for plants

When you boil rice or pasta, the water absorbs:

• Starch
• Small amounts of vitamins and minerals (like phosphorus, magnesium, and B vitamins)
• A tiny trace of protein

This is why pasta water for plants works as a natural fertiliser. These nutrients act as a mild plant food and soil conditioner, feeding beneficial microbes in the soil. It’s especially helpful for leafy greens, houseplants, and herbs. Think of it as a light, nutrient-rich tea for your garden.

Benefits of pasta water for plants and gardens

Using pasta water for plants has a few surprising advantages:

• Feeds beneficial soil bacteria, improving long-term soil health
• Gently boosts growth in herbs, leafy greens, and houseplants, especially in nutrient-poor soil
• Saves water by reusing what would normally go down the drain
• Free and natural — no packaging, no chemicals, no cost

It’s one of the simplest zero-waste garden hacks: good for your plants and better for the planet.

Using pasta water in the garden: step-by-step

How to use pasta water for plants

Follow these simple steps to use pasta water safely in your garden or with houseplants:

1. Let the water cool completely — hot water can damage roots and soil microbes.
2. Only use unsalted water — salt will dehydrate plants and harm soil.
3. Dilute if very cloudy — mix with plain water until it looks like weak tea.
4. Pour at the base of the plant — water the soil directly so roots absorb the nutrients.

How often?

Once every 1–2 weeks is ideal for most herbs, houseplants, and vegetables. Because it’s gentle, you don’t need to worry about overdoing it.

When not to use pasta water on plants

When not to use pasta water on plants

Although pasta water can benefit plants, there are times when it may do more harm than good:

• If the water is salted — salt dehydrates plants and damages soil health.
• If it contains oil, butter, or sauces — these coat the soil, blocking air and water absorption.
• For succulents, cacti, and orchids — these plants prefer lean, dry soil and don’t respond well to extra starches.

In these cases, it’s best to stick with plain fresh water.

Gardening doesn’t have to be expensive

Gardening doesn’t have to be expensive. Sometimes the best fertiliser is already in your kitchen.

Using leftover pasta, rice, or vegetable water for plants is one of those small, clever habits that adds up over time. It keeps your plants healthy, your soil nourished, and your household more sustainable.

We’ve poured hundreds of litres of cooled pasta and rice water over our own garden with great results. So next time you’re about to tip that pot down the drain, stop. Let it cool, and give your garden a free, zero-waste drink.