How Solar Exposure Affects Plant Watering Needs

We’re not so different from plants after all, at least when it comes down to some of our basic needs: hydration, nutrients, and survivable temperatures. For example, remember the last really hot day you experienced? Maybe you were lying by a pool, on the beach, or in a park. No matter where you were, chances are you were feeling pretty thirsty. That’s because when it heats up, humans require even more water. And plants? They operate in much the same way.

I’ll explain how solar exposure affects the watering needs of your plants, whether that’s grass on a lawn or the wide variety of vegetation that makes up a garden. We’ll cover all variables that determine plant watering needs, the specifics of how solar exposure makes your plants extra thirsty, and how to lower sun exposure and save money on your monthly watering bill, if your plant type thrives in shade. In other words: we’re about to shine a light on all your solar exposure gardening questions. Let’s get started.

What Determines the Watering Needs of Plants?

Before we get into how sun exposure determines the watering needs of plants, let’s give some context to just how variable water needs are. It’s not just sun exposure that changes how much irrigation plants require to thrive. This amount of water is also affected by climate, what type of soil is in your yard, what type of plants you have, and the stage of growth of those plants.

The Changing Climate

The climate is a massive variable, because it covers so many factors. The temperature, humidity, wind, and rainfall in your yard all influence how much water your plants will need. High temperatures usually require more water, high humidity less water, wind more water, and rainfall less water. You can probably see how this might get complicated when, for example, there’s rainfall on a hot, humid, and windy day.

The Specific Type of Your Soil

Your soil type will also affect how much water your plants need, but again, that contains a few different aspects. Soil texture, structure, and fertility all affect how well soil can hold and distribute water to your plants’ roots.

The Particular Type of Plant

On top of climate and soil type, different plants also just have different water needs. And while some experts recommend watering when the top inch of your soil is dry for the sake of simplicity, it’s always going to be best to know your plant types and to research their specific water needs.

The Growth Stage of Your Plants

How new is your vegetation? If your plants are on the younger side, they’re generally going to need more water than developed, mature plants. Sort of like how a growing child needs milk with a higher fat content than an adult drink.

How Does Solar Exposure Affect the Watering Needs of Plants?

Solar exposure is just one factor that affects plant watering needs. But how exactly does it work? Solar exposure increases the amount of water plants require because of three aspects: sunlight intensity, length of daylight, and the sun’s ability to increase soil temperatures.

Sunlight Intensity

Sunlight can cause water in the soil to evaporate through a process called transpiration. Transpiration occurs when plants absorb water from the soil through their roots and release it into the atmosphere through small openings in the leaves known as stomata. The release of water from the leaves cools the plant down and helps it maintain a balanced internal water system. However, this process also causes some of the water in the soil to—poof!—evaporate.

Length of Daylight

The exhaustion behind “It’s been a long day!” applies to plants, too. They generally need more water on longer days because they are growing and producing more leaves, which requires more water to support their increased metabolic processes. Longer days provide more hours of light, which stimulates photosynthesis and, therefore, growth.

Increased Soil Temperatures

It’s getting hot under there! Hotter temperatures are like a sunlight intensity and length of daylight combo. When soil heats up, it increases the rate of both transpiration and the metabolic rate of plants. So your plants’ increased need for a drink? It just multiplied.

How to Lower Sun Exposure and Save Water

If you have plants that require full sun, lowering exposure probably isn’t the right option for you. We want you to have a healthy yard, after all. But if you have plants that are getting a significant amount of sun and actually thrive in more shady conditions, here are some of the measures you can take to lower sun exposure—and save on your monthly water bill.

1. Plant shade trees: After tracking the sunlight throughout the day, place tall, leafy trees in strategic positions across your garden. These will provide shade and help reduce the amount of direct sun exposure your plants receive.
2. Install your own shade: Not into re-landscaping? Simply hang shade cloth and shade sails over garden beds or high above your garden to filter sun exposure.
3. Build shelter from the sun: This one looks great, too. Build a pergola or trellis over a garden bed to provide partial shade (that’s partial relief for your cooking plants).
4. Use mulch: A layer of mulch on top of soil in garden beds can help to reduce the amount of direct sun exposure, keep soil moist, and naturally fertilize. That’s three birds, one stone.
5. Plant in pots: If direct sun exposure in part of your garden isn’t going anywhere soon, the solution might be to get those plants out of there. Transfer your plants in pots and move them to a shadier location.

Watering Plants is Complicated! Here’s How to Make It Easier.

In addition to sun exposure, you know now that the watering needs of your plants are affected by climate, what type of soil is in your yard, what type of plants you have, and the stage of growth of those plants. That’s a lot of factors, and they tend to each contain multiple variables, like climate (humidity, rainfall, wind, temperature, oh my!). With all of these changing elements, it’s normal to feel confused about how much to water your lawn or garden.

Thankfully, there’s an easier way. The OtO device changes the game by taking the guesswork and gruntwork out of watering your plants properly. It analyzes different environmental factors such as local weather, windspeed, and temperature data. Then, it takes in the specific measurements of your lawn, even if it’s not regularly shaped, as well as considers the type of plants you have. Using that data, it adjusts its watering schedule, delivers the perfectly right amount of water to your lawn, and waters your actual lawn (as opposed to, well, the sidewalk). And irrigation is just one of its features—it also fertilizes, deodorizes, keeps away ticks and mosquitos, and so much more.

Now that you know the basics of how solar exposure affects the watering needs of your plants, there are sunny days ahead—but only if you want them!