The Guide to Watering Plants with Milk

Being compelled or coerced into drinking a glass of milk every day is an indelible childhood memory for most of us. We were often sternly tutored on the merits of milk consumption as we forced ourselves to finish a glass of what most of us found to be an unpleasant beverage at the time.

Not least of the benefits being touted was the fact that milk is high in calcium and will help us grow. Milk is an age-old source of rich nutrients that benefit not only the human body, but plants as well.

Using milk to water plants may sound like an unusual gardening practice, but enthusiasts are increasingly aware of its advantages and using it to nourish their plants.

? Article as a part of a series of articles “Watering plants with X-ingredient”. You can also read: watering plants with coffee, watering plants with sugar water.

Can you water plants with milk?

The short answer is, yes you can using milk to water plants, and it can be a nutritious alternative to plain water. Milk is packed with nutrients and disinfectant properties. It is also a healthy organic alternative to chemical fertilizers and pesticides.

A few precautions have to be observed while using milk as it can cause harm to some varieties of plants in concentrated form.

What are the advantages and disadvantages of watering plants with milk?


  • A common question that could arise is, do plants grow better with milk or water. The most obvious edge that milk has, is that it is a rich source of calcium. It can help build the cell walls of plants and help them grow to their maximum potential and stay resilient;
  • Calcium deficiency in plants is indicated by stunted growth and a condition called blossom end rot. A water-soaked spot appears at one end of a fruit and the decay spreads to the rest of the plant from there. Cucumbers, melons and tomatoes are some fruits whose plants are susceptible to it. Milk provides a strong defense against this condition by supplying the plant with sufficient calcium;
  • Milk is rich in proteins, healthy sugars and vitamin B, which promote plant growth and ensure a bountiful yield of fruits or flowers;
  • It contains lactoferrin, which is a strong bactericide and fungicide;
  • Chemical fertilizers and pesticides have harmful side effects but milk can provide nourishment and defense without that risk.


  • Milk contains fat that can hamper the plant’s ability to absorb water. It can dehydrate and eventually kill the plant. For this reason, milk should always be diluted before it is used in the garden;
  • Another drawback of the fat content is that it emits a foul odor as it decomposes. This can turn your garden malodorous. Taking care not to use excess milk can prevent this issue from occurring;
  • The bacteria that break down the lactose can cause the plant to wilt;
  • Dried skim milk should not be used in the garden as it has been linked to several types of plant rot like Alternaria leaf spot and black rot.

How should you water plants with milk?

  • Make sure that you dilute milk with plain water. The mixture should be equal parts of milk and water;
  • Avoid dried skim milk as they can cause a few types of plant rot;
  • This is a good way to put expired milk to use, as long as it is not spoilt;
  • Milk can be used to prepare a foliar spray, which is a way of introducing nutrients into the plant through the leaves. Plants absorb nutrition much faster through their leaves. The diluted milk can be filled in a spraying bottle or the sprayer attachment of a garden hose and sprayed on the leaves. A potential risk is that certain types of leaf fungus can develop if excess milk remains on them, in which case, the leaves can be rinsed off or wiped down some time after spraying;
  • The thumb rule to use while deciding the quantity of milk is five gallons per acre of garden;
  • The optimum frequency of fertilizing with milk is once at the beginning of the growing season and once in the middle of it.

What are additional ways to use milk in your garden?

  • Most plants require soil that is not too acidic or alkaline. If the soil tends towards either extreme of the pH range, it compromises the plant’s capacity to absorb nutrients from it. Milk can help balance the pH level of the soil. While milk is slightly acidic, its pH level is so close to the neutral value of 7 that it is considered neutral in many respects;
  • As a natural fungicide, it can help prevent powdery mildew that can develop on leaves;
  • Its antiviral properties can help fight mosaic leaf viruses like tobacco mosaic;
  • It is an effective organic pesticide that can fight aphid infestation and other soft-bodied pests that attack plants;
  • Rose bushes are vulnerable to black spots that are caused by a fungus. You can treat this condition by spraying a mixture of one part cow’s milk and two parts water on the afflicted leaves once a week until the problem is solved;
  • Soil needs to stay aerated as well as hydrated for plants to be able to draw nourishment from it. Milk enhances the ability of soil to absorb water and air. It also keeps the soil free of pathogens and insects, making it a healthy medium on which to grow plants.

With the spectrum of fertilizers and pesticides that are available in the market, gardening enthusiasts are spoilt for choice when it comes to plant care.

An organic alternative is always preferable, however, and diluted milk is a time-tested remedy that is healthy, safe and effective. Water plants with milk to achieve a lush, verdant and bountiful garden.