Can Morning Dew be Enough to Water Plants? Here’s How


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Dew can be beneficial when it comes to providing plants with additional moisture and reducing plant stress from drought conditions.

Dew can be used as a source of moisture for plants by placing them outdoors overnight until early morning. Water vapor condenses on leaves and is absorbed through the stomata while some fall onto the soil. Leaves with a larger surface area will increase the accumulation of dew and also the soil’s moisture content.

Indoor and outdoor plants can both accumulate dew on their leaves under the right conditions.

In this article, we are going to explore the many benefits of dew, how it affects plants and what you can do with your lawn to maximize its effects and promote healthy growth.

Can Dew be Enough to Water Plants

indoor plants in dew

Larger leaves can gather more dew and also the shade provided by larger leaves on the ground can prevent the sun from evaporating the moisture quickly.

Moreover, there is evidence that supports the claim that dew can be a source of moisture for plants. 

An article published by LUNA B. LEOPOLD, a leading U.S. geomorphologist and hydrologist, stated that from his experience about the consistency of dew in his area that 

The semiarid southwestern United States supports the view that dew is sufficiently frequent to constitute, in all probability, an important source of moisture for some plants.

Should You Place Indoor plants in the Dew

Placing indoor plants outside in the dew helps with water absorption through their leaves.

The increased humidity from the dew acts similarly to misting indoor plants but by more natural means.

For this reason, it was once recommended by a horticulturist at my local plant shop that I should also place my cactus outside in the evening to get some beneficial dew. But only overnight through the early morning until 8 am.

The moisture from the dew is enough to sustain plants such as cacti. Cactus plants love desert conditions and mostly receive their moisture from dew deposits.

The same goes for other indoor plants. Placing your indoor plants in the dew can have multiple benefits which we are going to expand on in the next point.

To take the guesswork out of determining how much moisture your soil has, you can use this cost-effective soil moisture meter from amazon.

XLUX Soil Moisture Meter

Benefits of Dew 

Helps plant revive from drought

Drought is an abiotic stress meaning that is mostly attributed to physical rather than a biological state in plants.

Plants when subjected to dew can gain that much-needed moisture. The due droplets accumulate on the leaves which are absorbed via the stomata into the plant. 

This directly increases the moisture within the plant and will also increase the moisture within the soil through the movement of water via the xylem from the leaves to the roots.

Additionally, the dew when accumulated on the leaf can also fall onto the soil beneath the plant helping to increase the soil’s moisture content.

Reduces Stress in Plants

Water stress in plants is caused as a result of drought or in the case of indoor plants, that hasn’t been watered for some time.

Drought not only affects plants through the reduction of water content, it also affects stomatal closure, limits photosynthesis and reduces the gaseous exchange between the leaf and the atmosphere.

Additionally, this gaseous exchange reduces transpiration and limits the uptake of minerals from the roots as water moves through the plant is restricted.

Dew provides relief to these above-stated, negative conditions as it helps the absorption of water through the leaves as the plant is distressed and the stomatal opening becomes relaxed.

Water absorption in plants (2)

Increases Humidity and Water Absorption

Dew is similar to misting and directly increases the humidity around plants and its ability to absorb moisture.

With an increase in humidity, it increases the leaf water differential between the atmosphere and the plant causing the stomata to open and absorb the water from the atmosphere.

Misting can be an alternative to placing plants in the dew as it provides the same conditions as dew but for a shorter period of time.

If you would like to know how to correctly mist your plants you can see our detailed article on misting here.

The Geniani portable humidifier from amazon provides the ideal environmental humidity for healthy plant growth. You can find it by clicking here.

geniani portable humidifier

Provides Cooling for Plants

As dew evaporates from the leaf it causes the plant’s temperature to drop.

Cooling occurs as the water changes state from a liquid to a vapor. In order for the water to do this, the water molecules require energy, in the form of heat, which is absorbed from the surface of the leaf, hence cooling the leaf as it evaporates.

This cooling effect is extended to the entire plant via the movement of fluids in the xylem and phloem throughout the plant.

Seed Germination

Helps Seed Germination

The effects of dew on the atmosphere can provide the ideal conditions for seeds to germinate. 

Adequate moisture and cool environments can be easily achieved with dew formation and with proper air and lighting environments seed germination can be easily achieved.

What is Dew point?

Dew is moisture from the air condensing onto the grass because the temperature passes below the dew point.

The dew point is the temperature to which air must be cooled to become saturated with water vapor. When cooled further, the airborne water vapor will condense to form liquid water. 

When air cools to its dew point through contact with a surface that is colder than the air, water will condense on the surface (source)

Where Does Dew Come From?

Dew comes from the moisture given off by plants through the process of transpiration. 

Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers.

Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism.

Transpiration

This can be utilized to water indoor plants. 

Other deeply rooted plants and trees that are well acclimated to the outdoor environment can harvest the water deep within the soil and through transpiration can give off water to the atmosphere which other plants can benefit from in the form of dew.

Placing indoor plants outside in the late evenings to the morning period can help water the plant through the condensation of dew on their leaves which will in turn drip on the soil beneath.

The Effects of Dew on Lawn Grass

Lawn grass will have the same benefit as indoor plants. Lawn grass can also benefit from dew.

Although water is lost from transpiration, adapting certain lawn care habits like cutting the grass a little taller can go a long way in providing water for the grass.

Consider mowing the lawn such that the blades are long enough to help retain moisture.

Longer grass blades approximately 3 to 4 inches, will create a larger surface area for dew to condense. 

Additionally, with longer blades, the shading cast by the grass on the soil beneath can help in preventing moisture from being evaporated from the sun as it moves through the day.

dew on grass

Although the grass may get moisture from dew you should monitor its growth and if it shows signs of dehydration you can incorporate a watering schedule of applying water for 15 minutes by a sprinkler about once or twice a week to drench the soil and help promote deep and healthy root growth.

Lawn grass typically requires about 1 inch of water per week to sustain healthy growth.

Watering via sprinkler should be done in the morning before 10 am which can help with cooling during the day and also prevent diseases.

To increase the effects of moisture within the soil of lawn grass consider the movement of the sun and how it is affected by the shade of larger trees. 

The shading can considerably reduce surface temperatures and with that, evaporation.

Even the structure of the house as the sun moves lawn grass and plants around the house can get only half a day of sun as it moves from east to west.

Therefore proper positioning of plants with regards to larger structures can help in the prevention of evaporation and loss of moisture from the soil.

morning sun

Morning Sun vs Evening Sun

Morning sun is thought to be better than evening sun. This is because as the sun moves throughout the day from morning to evening the air becomes drier and the temperature increases and humidity decreases.

Morning sun is less harsh as the air still has moisture or increased humidity from the dew, this provides a shielding effect that reduces the full effects of the sun. 

As the day gets hotter and the dew evaporates the temperature on the surface of the plants is reduced as the water turns into vapor again.

Therefore placing plants and lawn systems to get mostly morning sun in relation to larger structures can be very effective in the conservation of soil moisture.

What the overall effect this has is on the water consumption in watering lawns in the hotter summer months of the year not to mention the saving that goes along with it.

Can Dew Provide Nutrients for Plants

As far as analytical data go, dew can provide small amounts of minerals to the plants.

From research done by the Institute of Civil Engineers and Architects, Ahmedabad, a sample of dew was collected and analyzed by a lab in India and these were the findings 

Tested ForQuantity Found
EC (electrical conductivity)0.24 dS / m
pH7.70
TDS (Total Dissolved Solids)154 ppm
Ca+2 + Mg+2
(calcium and magnesium
1.50 me / lit  
Na+ (Sodium)1.00 me / lit  
CO3 -2Trace 
HCO3 – 1.25 me / lit
Cl1.50 me / lit 

This test was done in India with different climatic conditions than that experienced here in North America.

The region and climatic conditions can affect the type and amount of nutrients that are present in dew. 

As a result, different regions will have different nutrient compositions in dew samples.

JayLea

JayLea has a passion for plants and has been gardening since 2015. He has valuable knowledge about gardening and houseplant care and can answer everyday practical questions that every plant owner has.

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