What is the Best Water Temperature for House Plants

Although caring for house plants may sound like a simple task, there are several factors of their care one must pay attention to. Among these factors is the temperature of their water.

House plants can usually be watered with water between 60 to 70 degrees Fahrenheit. Within that range, the optimal water temperature to water a house plant is 68 degrees Fahrenheit. Certain circumstances may dictate the use of a water temperature outside this range.

Whether you are a seasoned house plant caretaker or are just getting your first plant, paying attention to water temperature may be something you never considered. You should water your house plants at the correct temperature to facilitate growth and prevent illness. Keep reading to learn more about the proper water temperature to use with your house plants!

Why Water Temperature Matters

Before discussing the optimal temperatures for watering house plants, it is important to know why water temperature matters. Knowing the importance of water temperature will help you better understand how to water your house plants in different circumstances.

When watering our house plants, the water is most often directed at the base of the plant. Why is this? This is done because the roots absorb water better than the leaves.

Watering the roots instead of the leaves means the plant will absorb more water and stay better hydrated. However, this also means that the roots, the most sensitive part of the plant, are exposed to varying water temperatures.

Using the wrong water temperature could damage the roots and lead to the plant’s demise. However, using cold or hot water on your house plants will affect the plants in different ways.

Plants use water temperature to determine how much water they should absorb. At lower water temperatures, the roots do not activate and do not absorb enough moisture to survive.

On the other hand, higher water temperatures damage the roots and can lead to mold or bacteria growth.

In any case, watering your house plants with an extreme water temperature will shock the roots. This will stress the plant until it dies. Think about how plants receive water in nature. The water is usually within natural limits and isn’t heated or cooled to extreme limits. If you’re using water from the kitchen sink, you have access to a much larger range of temperature than these plants would encounter in natural settings.

Avoid watering your plants with water that is either too cold or too warm. But what is the ideal temperature to water your house plants at then?

The Perfect Water Temperature

There are varying opinions about the exact temperature to water your house plants at; however, the consensus is to use room temperature water.

This range typically includes water between 60 and 70 degrees Fahrenheit. Anything warmer or colder will damage the roots and likely kill the plant.

According to CANNA, the sweet spot for watering house plants is 68 degrees Fahrenheit. At this temperature, the roots are triggered to absorb water easily. Additionally, water at this temperature has more oxygen than at other temperatures. This extra oxygen helps the plant immensely.

An employee at Paradise Nursery in Idaho suggested watering your house plants at room temperature. In most circumstances, this will keep your plants healthy.

Although many agree that room temperature is the optimal water temperature for watering house plants, some rumor that using warmer or colder water will lead to better growth and flowering.

Let’s discuss the different effects using warmer or colder water will have on house plants. Afterward, you can decide for yourself whether the rumors are true or not.

Using Hot Water

As mentioned earlier, using hot water on plants shocks the roots and can lead to bacteria or mold growth. However, this is not the only damage hot water causes to house plants.

When a plant is watered with hot water, it undergoes “heat stress” and begins to wilt. This can also lead to scalded foliage. Your plants have scalded foliage if the leaves look shriveled or burnt.

If the hot water is poured over the leaves, it can melt off the leaves’ protective coating increasing its chances of contracting disease or illness.

Watering plants with hot water not only affects the plant itself. Hot water can kill off the microorganism in the soil. Without these microorganisms breaking down nutrients in the soil, the plants will starve and die.

Do you still think watering your plants with hot water is a good idea? Let me give you something else to consider. Hot water is often used to kill weeds. Many gardeners boil water and pour it on pesky weeds in their flower beds. Should you use a tactic used to kill plants to keep your plant alive? Probably not.

Using Cold Water

Some also believe that watering with colder water will help plants survive warmer days and promote flower blooms. So what does cold water actually do to plants?

Like hot water, cold water can damage the plant’s roots. However, the extent to which cold water damages the actual plant is minimal. Watering your house plants with water that’s too cold will shock their roots and eventually kill the plant.

Meanwhile, mildly cold water will signal to the roots that it should not absorb the water. This will lead to dehydration and eventual plant death.

When to Water House Plants

As well as the actual temperature of the water, another factor to consider is when to water your house plants.

Throughout the day, your plants are exposed to different air temperatures. The air temperature can be taken into consideration when watering your plants.

Most gardeners agree that the best time to water plants is in the morning. The cooler air combined with the room temperature morning will not shock the roots and will start the plant off with the moisture it needs to survive throughout the day.

If cooler times of the day are the best time to water plants, why not water your house plants in the evening?

Watering a plant in the morning allows the roots to absorb the water throughout the warmer part of the day. However, when you water your plants at night, there is no need to absorb all the water.

Letting water sit on the roots all night long will increase the plants’ chances of getting fungus infections and dying.

If the plant does not develop a fungal infection, it could become dehydrated. As the water evaporates, the plant will not have the water it needs to survive the heat of the day.

You may conclude that watering your house plants in the middle of the day is the answer to keeping your plants hydrated. Although this sounds like it would work, it will actually do the opposite.

Watering in the heat of the day, although better than not watering at all, does not provide the plant with enough water to survive. Because of the higher air temperatures at mid-day, watering at this time results mostly in evaporation.

If you are watering your house plans at a warmer part of the day, you may slightly increase the temperature of the water you use. Matching the water temperature to the air temperature will prevent you from shocking the roots. However, the water temperature you decide to use will vary throughout the day.