Can You Water Plants On A Hot Day? (Ideal Time To Water)


Yesterday was a very hot day, and some of the plants in my garden were looking a little wilted, as temperatures soared to over 90 degrees Fahrenheit (32 degrees Celsius).  I began to wonder if it is a good idea to water plants on such a hot day, or if it can harm them in any way.

So, can you water plants on a hot day?  Yes, you can water plants on a hot day – the leaves of plants will not get scorches or burn spots if they get wet on a hot, sunny day.  However, you should check the soil to be certain that your plants actually need water before you water them.  The best time to water is in the early morning, before the sun comes up and starts to evaporate any water you pour on the soil.

Watering your plants early on a hot day saves water and time, since your soil will lose less water due to evaporation.  However, there are some other guidelines to follow when watering your plants on a hot day.  Let’s get into some of the details, including when to water, how to water, and some dos and don’ts of watering.

Can You Water Plants On A Hot Day?

Yes, you can water plants on a hot day, but first you should make sure that they really do need water.  If your plants do need water, then you should plan on watering at the ideal time to save time and make your water go further.

So, how do you tell if your plants really do need water?  Some gardeners will look at the plants themselves to see if they are wilted, but that is not the best way to tell.  Let’s look into this further.

Should You Water A Plant If The Leaves Are Wilted?

No, you should not necessarily water a plant whose leaves are wilted.  This is a common mistake that many beginner gardeners make.

wilting cucumber plant
Wilting cucumber plant, courtesy of user Sohmen at Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Photo-of-a-real-wilting-cucumber-in-greenhouse.jpg

When you water a plant that does not need it, you risk “killing the plant with kindness” by over watering.  Over time, a plant whose roots sit in soggy, wet soil will develop root rot or other diseases that can eventually kill the plant.

roots
Root rot causes roots to turn brown and mushy.

A plant that is over watered may become unable to absorb enough water through its damaged roots.  This can give its leaves the same wilted, droopy appearance as the leaves of a plant that is dried out.

If you continue watering at this point, the problem will only get worse. For more information, check out my article on over watering your plants.

The only way to tell whether your plant really needs water is to check the soil right next to your plant.  First, use your fingers to dig down 2 or 3 inches into the soil.  Avoid using a sharp garden tool, since this can damage the roots, especially if they are shallow.

If the soil is dry at a depth of 2 or 3 inches, then you should water your plant.  Otherwise, it is ok to wait a while before you water the plant again.

When Should You Water Plants On A Hot Day (Ideal Time To Water Plants)?

If the soil is dry a few inches down and your plant’s leaves look wilted or droopy on a hot day, then you should water the plant immediately.  This will save the plant from drought and prevent common problems due to inconsistent watering, such as blossom end rot in tomatoes and peppers.

A few tomatoes with blossom end rot, which can be caused by uneven watering (too little and then too much water).

Going forward, you should aim to water your plants in the early morning, in order to make the most of your time and water supply.

That way, you avoid watering in the hot sun of the late morning and early afternoon, which will evaporate water from the soil more quickly.  This also allows you to avoid spending too much time out in the hot sun!

Avoid watering late in the evening, since the sun will be going down, and there might not be enough time for the water to dry off of the leaves of the plant.  This can increase the chances that your plants will suffer from mold or other diseases that thrive in wet conditions.

Other Common Questions About Watering Plants

There are some other common questions about watering plants, so let’s try to get a handle on some of those.

Should You Water The Leaves On A Plant?

It is ok to water the leaves on a plant, but only occasionally, and under the right conditions.

You should water the leaves on a plant once in a while, especially when the weather has been hot and dry without any rain.  This allows you to rinse off the dust, dirt, pollen, and other debris from the leaves of your plants.

When the leaves of a plant are clean, they are able to absorb more sunlight for photosynthesis, improving their energy production and growth rate.  This might explain why plants seem to grow well after a long, hot dry spell followed by a rainstorm.  The leaves are clean and the soil is wet, so the plant can get more light and water for photosynthesis.

rain splashing on plant
You should only wet a plant’s leaves on occasion, such as if they are dusty after a long, hot dry spell.

If you must wet the leaves on your plants to rinse off debris, do so in the late morning or early afternoon.  This will give the sun plenty of time to help the water to evaporate from the leaves of your plants.  If you wet the leaves too late at night, they can stay wet for too long, which invites mold and other plant diseases.

Some people believe that watering plants during a hot day when the sun is bright will scorch or damage the plant’s leaves.  However, this is not true, since the water does not stay on the leaves long enough to allow sunlight to become concentrated and burn the leaves.

According to Dr. Gabor Horvath, a researcher, there are other reasons that a plant’s leaves become scorched.  “For example, drops of acid rain, salty sea or tap water, chlorinated water and concentrated solutions of fertilizer or other chemicals can all cause sunburn-like brown patches.” (Dr. Horvath’s words).

For more information, check out this article from the Telegraph about how watering on a hot, sunny day does not cause leaf burn on plants.

In summary, you should generally avoid wetting the leaves of your plants, but it is ok once in a while.

How To Water Your Plants To Avoid Waste

Maybe you live in a town that has imposed watering restrictions, or the water is very expensive.  Perhaps you simply want to do your part to conserve water.  Either way, there are some steps you can take to avoid wasting water.

First of all, you should pour the water low, right near the soil.  Avoid wetting the leaves of your plant, since most of this water will evaporate during the day, due to the sun.

Also, water deeply, to give the water a chance to find its way further down into the soil and to the plant’s roots.  Watering shallowly and frequently will allow the sun to evaporate more of the water, and it will also encourage the growth of weak, shallow root systems.

tomato plant roots
Deeper, infrequent watering for mature plants encourages the growth of stronger root systems.

In addition, make sure to water all around your plants, in order to encourage larger, more widespread root systems.  The strength of a plant’s root system is one of the biggest factors that will determine whether the plant survives a hot day when you are not around to water constantly.

Finally, cover the soil near your plants with mulch in order to help the soil retain moisture.  You can use straw, wood chips, pine needles, leaves, or grass clippings as mulch.

Any of these materials will provide insulation and prevent the sun from evaporating water from your soil.  As an added benefit, they will eventually decompose and provide additional organic material for your garden soil.

Do Plants In Containers Need More Water?

Yes – plants in containers tend to lose water to evaporation faster than plants in the ground.  Also, remember that clay pots allow water to evaporate more quickly than plastic pots. For more information, check out my article on clay versus plastic pots.

clay pots
The soil in clay pots will dry out more quickly than soil in plastic pots.

In addition, glazed clay pots with darker colors will heat up quickly in the sun, so be careful on a hot day if you have heat or drought sensitive plants outdoors in glazed clay pots!

As with any plants, the best way to tell if you need to water your container plants is to feel the soil with your fingers, down to a depth of 2 or 3 inches.  If you consistently have trouble with dry soil, there are some ways to help your soil retain moisture, including the addition of compost.

For more information, check out my article on how to treat dry soil.

Conclusion

By now, you know that it is fine to water plants on a hot day, but that you should try to water in the morning.  You also know that there are some measures you can take to prevent your plants from getting damaged in the heat.  Now it’s up to you to take action and save your plants from heat and drought!

I hope you found this article helpful – if so, please share it with someone who can use the information.  If you have any questions or advice about watering plants on a hot day, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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