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The Surprising Plant Fertilizer You’ve Already Got in Your Fridge

Tehrene Firman

June 16, 2020

water plants with milk — Photo: Getty Images/RgStudio

Once the milk in your fridge has expired, there's really nothing you can do but dump it down the sink. Or so I thought, anyway. As strange as it sounds, you can actually water plants with milk. Even if you can't drink it yourself, it makes for a stellar fertilizer.

According to Gardening Know How, expired milk is loaded with calcium, protein, vitamins, and sugars that can help give your plants an added boost and help them grow big and strong. And while milk isn't something your plants need all the time, it's a great way to recycle something that would normally go to waste, making it beneficial your plants and the planet.

The next time you have milk past its due date sitting in your fridge, start by diluting it so you're working with equal parts water and milk. Then, either put the mixture in a spray bottle and spray your plants' leaves (like if you're spraying garden plants outdoors), or lightly pour it around the base of your plants like you're watering them (if you're working with plants inside your home).

A warning: Too much of a good thing is definitely possible when it comes to watering plants with milk. "Using too much milk isn’t a good idea since the bacteria in it will spoil, resulting in a foul odor and wilty, poor growth. The fat in milk can produce unpleasant odors as it breaks down as well," writes The Spruce.

While all garden plants and houseplants can benefit from those added nutrients, Hunker says the method also has the added bonus of being able to help fight off fungal diseases like powdery mildew in jade plants, English ivy, and angel wing begonias (TIP: Unsure if your plant is prone to mildew? Find out using a plant identification app.) So, what are you waiting for? Don't let another drop of your spoiled milk go to waste ever again.