Using Pasta Water to Feed Your Plants: Pasta Water For Plants

Cooking pasta leaves behind a starchy, nutrient-rich liquid that most people simply pour down the drain. But did you know that pasta water can be used to feed and fertilize your plants? The starch, vitamins, and minerals found in pasta water make it an excellent supplement to your plants’ regular watering routine.

Why Pasta Water is Good for Plants

When pasta is boiled, starches from the pasta leach into the water. This leaves the water high in carbohydrates, vitamins, and minerals that plants can absorb through their roots and leaves.

Specifically, pasta water contains:

  • Starch – Provides carbohydrates and energy for plants
  • Iron – Important for plant respiration and photosynthesis
  • Calcium – Helps build cell walls and strengthen stems
  • Magnesium – Aids in chlorophyll production and fruit development
  • Potassium – Helps plants resist disease and supports water regulation
  • Sodium – Improves drought tolerance and stimulates growth

The nutrients in pasta water can boost plants’ growth and blooming. The starch provides fuel for beneficial microbes in the soil. And the vitamins and minerals act as an organic fertilizer to nourish plants.

Using Pasta Water Safely and Effectively

While pasta water offers proven benefits, there are some caveats to using it safely. Here are some key tips:

  • Use plain pasta only – Avoid any pasta made with added oils, salts, or seasonings. The goal is to utilize the starch, not introduce other elements. Stick to basic pastas like linguine or penne with no additional ingredients.
  • Cool the water first – Waiting until the water reaches room temperature prevents shocking plants with hot liquid. Let it cool completely before using.
  • Dilute it – Full strength pasta water can be too intense for plants. Dilute it with an equal amount of plain water to create a milder mix.
  • Use sparingly – While the nutrients are helpful, plants don’t need huge amounts. Use pasta water every 2-3 weeks and alternate with regular waterings.
  • Avoid leaves – Only use pasta water for soil application, not as a foliar spray. The starch can leave an unsightly residue on leaves.
  • No salt – Never use salted pasta water, as the sodium content can damage plants. Stick to unseasoned pasta only.
  • Prevent mold – Don’t store pasta water more than a day or two. The starches can feed mold growth. Apply immediately for best results.
  • Outdoors only – Unless very diluted, indoor plants may struggle with the extra nutrients. Use pasta water for outdoor gardens and potted plants.

By following these guidelines, you can safely unlock the advantages of pasta water for your plants. Always monitor plants closely and adjust your usage if any issues arise.

Best Plants to Use Pasta Water On

While most plants can benefit from an occasional pasta water feeding, some varieties respond especially well. These plants make ideal candidates for enriching with leftover starchy liquid:

Tomatoes – The additional potassium and calcium in pasta water helps tomatoes grow strong and produce abundant fruit. It prevents blossom end rot.

Peppers – Like tomatoes, peppers thrive with the calcium and potassium boost. Their spicy fruits will grow vigorously.

Basil – Basil loves rich, fertile soil. The nitrogen in pasta water makes leaves grow faster and boosts essential oil production.

Lettuce – The moisture retention of pasta water keeps lettuce evenly hydrated for crisp, tender leaves. Starch also limits wilting.

Carrots – Often needing extra potassium, the starchy drink helps carrots grow long, robust roots with excellent color.

Chard – Supporting big, healthy leaves, pasta water satisfies chard’s thirst for nitrogen and potassium. Growth explodes.

Cucumbers – Heavy feeding cucumbers appreciate the extra energy, resulting in higher yields of juicy fruits.

Squash – Also hungry plants, zucchini and summer squash benefit greatly from the nutritional support of pasta water.

Broccoli – The additional magnesium and calcium from pasta water minimizes florets with hollow stems.

Fruit trees – Stone fruits, citrus, and others develop sweeter fruits with more minerals from pasta water.

Customize usage to your own plants’ needs, but these varieties see excellent results from occasional pasta water fertilizing.

How to Use Pasta Water on Plants

Pasta water should always be allowed to cool to room temperature before using on plants. Water that is still hot can damage roots and leaves.

For most plants, dilute the pasta water with an equal amount of plain water before feeding it to plants. The starch can leave residue on plant leaves if used full strength.

Here are some easy ways to use leftover pasta water for your plants:

Watering Can

  • Allow pasta water to cool completely, then dilute it 1:1 with plain water.
  • Use the diluted pasta water to water container plants and garden beds as part of your regular watering routine.
  • The goal is to replace 25-50% of plain water with diluted pasta water every 2-4 weeks.

Soil Drench

  • Dilute room temperature pasta water 1:1 with plain water.
  • Slowly pour the diluted pasta water directly over the soil around your plants. Avoid getting it directly on the leaves.
  • This method is great for helping nutrients penetrate to the root zone. Do it every 3-4 weeks.

Compost Tea

  • Fill a 5 gallon bucket about halfway with compost.
  • Fill the bucket the rest of the way with diluted pasta water. Use a 1:1 ratio with plain water.
  • Let it steep for 5-7 days, stirring occasionally.
  • Strain the compost tea and use it to water plants or pour directly on the soil.

Foliar Spray

  • Allow pasta water to cool completely then dilute 2:1 with plain water.
  • Pour the diluted pasta water into a spray bottle.
  • Mist plant leaves, stems, and buds with the foliar spray. Avoid doing this in direct sun.
  • The nutrients and carbohydrates will absorb right through the leaves.


  • Pasta water can be used to supplement hydroponic systems.
  • Dilute cooled pasta water 5:1 with plain water.
  • Replace 10-25% of the normal hydroponic nutrient solution with diluted pasta water.

With any application method, be careful not to overdo it with the pasta water. Use it as a supplement no more than every 2-4 weeks. Too much starch and nutrients can overwhelm plants’ systems.

Making the Most Nutritious Pasta Water

To get the biggest nutrient bang for your buck, follow these tips when cooking pasta for use in your garden:

  • Use whole grain or veggie-based pasta instead of plain white pasta. These have more vitamins and minerals.
  • Avoid adding oil or salt to the pasta cooking water. These will not benefit your plants.
  • Use a large pot with lots of water so you end up with more pasta water for your plants.
  • Boil pasta for 2-3 minutes less than package directions for firmer texture. This leaves more starch in the water.
  • Save water used to cook longer pasta shapes like spaghetti. More surface area leaches more starch.
  • Toss your pasta with sauce in a bowl rather than the cooking pot. This preserves the purity of the water.
  • Let pasta water cool completely before diluting and using so you don’t damage plant roots or leaves.

Follow these best practices, and you can feel good about recycling your leftover pasta water to make your plants happy. It’s a simple, free way to fertilize plants and reduce waste. Your garden will reap the benefits of this nutritious kitchen byproduct!

Here is a simple recipe to try:


  • 2 cups pasta water
  • 2 tbsp Epsom salts
  • 1 tbsp baking soda
  • 1 tbsp molasses
  • 1 crushed eggshell


  1. Allow pasta water to cool completely after cooking plain pasta.
  2. Pour 2 cups of cooled pasta water into a jar or pitcher.
  3. Add Epsom salts, baking soda, molasses, and crushed eggshell.
  4. Stir thoroughly until fully dissolved.
  5. Use within a few days by diluting 1 part plant food with 4 parts regular water.
  6. Apply diluted plant food around the root zone every 2-3 weeks.

Frequently Asked Questions About Using Pasta Water on Plants

Is pasta water safe for all plants?

Most plants can safely absorb the nutrients in pasta water when it is diluted appropriately. However, it’s best to avoid heavily salted pasta water, as the salt content could damage sensitive plants. It’s also wise to start with a mild 25% dilution and monitor your plants’ response.

How often should I feed plants pasta water?

In general, supplementing your plants with diluted pasta water every 2-4 weeks is sufficient. Too much starch and sugars can be counterproductive, causing issues like fungal diseases. Think of pasta water as a boost, not a routine fertilizer.

Is pasta water a replacement for fertilizer?

No, pasta water does not contain the complete balance of nutrients that plants need. It should be used as a supplemental fertilizer to boost macronutrients, vitamins, and minerals. Regular, balanced fertilizer should still be used as directed.

What type of pasta makes the best water for plants?

Opt for whole grain or vegetable-based pastas over plain white varieties. The darker colors indicate more B vitamins and minerals that will benefit plants. Shape doesn’t matter too much, but longer shapes may impart a bit more starch.

Can I use pasta water on edible plants?

Yes, diluted pasta water is safe for fruits, vegetables, herbs, etc. The nutrients it provides actually improve the growth and flavor of edible plants. Just be sure to use pasta cooked without added salt, oil, or seasonings.

How long does pasta water last before using on plants?

Fresh pasta water is best. For optimal nutrient content, use leftover pasta water within 2-3 days. If saving it longer, refrigerate and use within 5-7 days. Discard if any odd smells develop.

Is it okay to use salted pasta water on plants?

Avoid using salted pasta water on most plants. Though some plants tolerate salt, for most varieties, the sodium and chloride levels can do more harm than good. Stick to pasta cooked in plain water.

Final Thoughts

Using your leftover pasta water is an ingenious way to get double duty out of water, save money on fertilizer, and boost your plants’ health. Follow these tips to safely feed your garden pasta water without wasting this precious resource. Your plants will thank you for it!