The Best Time of Day to Water Plants

Water your plants in the early morning if you remember only one rule from this article. There are, of course, nuances that depend on your soil type, climate, and plant species you grow.

A few years ago, I lost a rosemary plant to the root rot because of my consistent evening watering practice. Apparently, everything else I did right, but the timing was still wrong. And that got me thinking about the importance of watering at a certain time.

Why Timing is Important in Watering Plants

There’s a wealth of advice online about how often and how much water a plant needs. Timing is always a secondary aspect of watering. But in reality, it has a lot to do with how much of the water gets absorbed by the plant.

The soil temperature, air temperature, humidity level, and even sunshine levels change throughout the day and influence the behavior of water on the surface of your garden. Water poured on warm soil evaporates differently from the water poured on the cold one. Much of the water poured mid-day evaporates before it has a chance to reach the root of the plant.

Early Morning is the Optimal Time

For most plants, watering in the early morning is recommended. It ranges from 6 am to 10 am and depends on your geographical area.

• Lower temperature reduces evaporation rate. The water has time to be absorbed by the soil.
• Plants have time to get hydrated before the heat of the day comes. It is particularly important in summer, when the heat stresses plants that were not properly hydrated.
• The foliage will have enough time to dry up in the sun rays and will not create ideal conditions for fungi and other pests.

The third point here is the most critical. Overly moist leaves overnight are a perfect invitation for fungus and other diseases. Especially in humid climates and gardens with a high density of plants and poor airflow.

If you have a drip irrigation system or soaker hoses, you still need to stick to the morning watering pattern. The temperature and evaporation rates will remain the same.

Why Evening Watering Might Be Wrong for You

Evening watering is not wrong per se. But it is risky and the level of the risks depends on your specific situation.

The idea is clear – cooler temperatures, absence of wind, low evaporation level in comparison with mid-day watering. It allows the water to go deeper into the soil.

In hot and dry climates, some people choose to water their plants in the evenings because the daytime heat makes the water evaporate quickly. So evening watering is more efficient in such climates.

But evening watering has one major drawback – there is moisture sitting on the leaves overnight, when the sun cannot dry them up. It leads to fungal diseases in humid climates or crowded garden. I know a person who suffered the tomato plants’ blights for two weeks because of this issue.

If evening watering is your only option because of work schedule or watering timer, water the base of the plant instead of using sprinklers. Also, try to water earlier in the evening and not right before the dark time.

Why Midday Watering Is Pointless Most of the Time

Watering in the middle of the day, particularly between 12 am and 3 pm in summer is strongly discouraged by most gardening guides.

Because the temperature and sunshine are at their peaks, much of the water poured mid-day evaporates before reaching the root zone. So you spend more water on evaporation than on watering the plant itself. If you are water-conscious gardener or have metered water supply, it will frustrate you.

As for the old myth about midday leaf burns due to the magnification effect, it was already debunked. Evaporation and inefficiency of watering midday are the actual reasons why watering midday is not a great choice.

But if your plant looks wilted and stressed by the heat, you need to water it now and not follow some schedule.

Does the Timing Depend on the Type of Plant or Climate?

Yes, it does. Some generic advice might not be applicable for your case.

• Indoor plants do not have to worry about direct sunshine and wind. They lose water slower and are not affected by the time of the watering. Morning is, of course, a good choice because it coincides with the time when the person moves around the house.
• Succulents and cacti do not care about the timing because they need infrequent and deep watering. Whether you water at 7 a.m. or at 7 p. m. is not so important as to make sure the soil is dry enough between waterings.
• Vegetables and leafy greens will benefit most from the strict morning watering routine because of the higher fungal diseases threat and higher transpiration rate.
• In hot and arid climates, some gardeners water their plants in the very early morning, ideally – before sunrise, because the morning time is already too hot for a proper watering.
• Gardeners in humid and temperate climates should pay special attention to the morning watering because of the fungal disease threat.

A Simple Way to Check Your Watering Efficiency

Forget about the clock for a moment and pay attention to the soil.

Stick your finger into the soil up to 2 inches. If it feels moist, then skip that watering, regardless of the time. Because overwatering on schedule is one of the most common mistakes of otherwise caring plant owners.

Also, pay attention to the leaves. Consistent wilting in the morning, before the heat comes, might indicate watering problems.

Is it bad to water plants at night?

Not necessarily. But it increases the risk of fungal diseases in humid climates or plants with dense foliage. If night watering is your only option, water the base of the plant and try to avoid wetting the leaves.

Can I water plants in direct sunlight?

Of course, you can. But it will be inefficient. Much of the water will evaporate before reaching the root and it is not a good spending of your time and water bill.

How early is too early to water in the morning?

There is no “too early”. It is safe to water plants before sunrise. And in very hot climates, it is sometimes preferable because it gets ahead of both the heat and evaporation.

Do potted plants need a different watering time than the garden plants?

No, not so much. Potted plants just dry out faster because of the smaller volume of the soil. So, they might need more frequent watering but morning is still the preferable time for the same reasons.

Conclusion for Your Watering Can

If you remember only one rule from this guide, then it is the morning watering. Adjust it for your climate and rely on the soil instead of the clock. A dead rosemary plant taught me that lesson.