Garden Watering Frequency: Best Practices

By Erin Marissa Russell

Let’s talk about garden watering frequency. Everyone knows that plants need water, but when it comes to keeping your garden well hydrated, things get a little complicated. Plants need to get just the right amount of water, which must get to their root systems without keeping foliage and soil too wet. The soil needs to retain moisture to keep it available for plants while still draining well. So how often should you water, and for how long? Here’s a guide that should help you figure out your needs.

Gardeners must choose between watering their plants using a watering can, garden hose, sprinkler system, or one of the various irrigation methods. And especially during the hottest times of year in certain climates, water conservation becomes very important. So what’s a gardener to do? Just keep reading—we’ve got you covered with this all-in-one guide to watering the home garden that will tell you everything you need to know to provide your plants with the water that will keep them flourishing and healthy.

How Water Moves Through the Soil

When you water your plants the water doesn’t simply stay in the ground for them to use later—and it doesn’t start trickling through the layers of earth from the very beginning, either. Soil is divided into layers, and each one of these layers needs to be hydrated to field capacity before the moisture can move down into the next layer. The way water moves through these layers of soil is called the wetting front, and here’s what you need to know about it.

Hydration will drip through the layers of a sandy, coarse soil more quickly than it will through other types of soil, such as silt or clay.

Moisture doesn’t spread evenly through the top layer of the ground when an insufficient amount is applied. Instead, if you give your garden half of what it needs, only the top half of your plants’ root zone will receive water. The wetting front will stop halfway down, offering no moisture to the part of your plants’ root system that is in the bottom half of the root zone.

When hydration reaches the root zone, the root systems of your plants begin to absorb the water, which moves upward through the plant to its foliage and fruits or flowers. Water vapor then begins to evaporate through the microscopic openings in each plant’s leaves called stomates. The process that causes water to leave the plant via evaporation is called transpiration, and it results in wilting unless plants receive a consistent supply of moisture delivered to their root zone. Transpiration is also responsible for cooling down the surfaces of your plants.

Simply providing your garden with the amount of water that plants require isn’t quite enough. Instead, your garden needs the amount of water plants will lose via transpiration plus what will evaporate from the soil. Taken together, these two processes go by the name evapotranspiration. The amount of water lost in evapotranspiration changes depending on how long the days are, what the temperature is, what the weather is like, whether the ground is mulched, how many plants are in the garden, what type of plants need the water, and how large those plants are.

Signs that Plants Need More Water

It can be tricky to know just how much water your plants need to thrive, especially when you’re aware of the dangers of overwatering and are working to prevent it. Here’s a list of signs that your plants aren’t getting enough hydration.

Rolled-up leaves

Wilted foliage

Discoloration to brown at the tips of leaves and along their edges

Leaves that change the direction they’re facing (but not in order to face the sun)

Less growth of leaves and stems than usual

Reduced harvest

Signs of Overwatering

Just as important as ensuring that your garden gets adequate hydration is being careful not to overwater your plants. When too much water is provided, excessive moisture in the environment can open your plants up to infection by various fungal diseases. Note that some of the symptoms of overwatering can resemble underwatering, so it’s important to pay close attention to just how much water you’re providing your plants and compare this amount to how much they need. Alternatively, you can perform a soil moisture test as described in the section “Tips for Watering the Home Garden” before you water the garden. Here are the signs of overwatering to watch for in your plants.

Discoloration to brown of leaf tips or the area along the edges of leaves, which progresses to complete discoloration before leaves eventually fall from the plant

Death of parts of the root system due to insufficient water—once root damage occurs due to overwatering, plants are unable to take in sufficient hydration and will begin to show signs of drought stress as listed in the section “Signs That Plants Need More Water”

Tips for Watering the Home Garden

To determine whether your plants are ready for their next dose of hydration, there’s a simple test you can do in just a few seconds. Simply insert your finger into the soil near where plants are growing (in the root zone). If the ground feels damp, or if soil clings to the skin of your finger, the ground is still damp, and it isn’t yet time to water your plants again.

Lack of water is most harmful to plants during certain periods in their development, and it’s during these times that it’s most vital they receive sufficient moisture. Make sure to give your plants adequate hydration when seeds are germinating and also when seedlings begin to sprout up out of the soil.

When you transplant seedlings into the garden, they should be provided with water immediately.

Ensure that when you water your plants, you’re giving them the right amount of hydration. A light sprinkling of moisture isn’t sufficient, no matter how often you provide it. Even frequent doses of water that lightly sprinkle the soil with moisture only wet the ground to a soil depth of one inch. However, the root systems of your plants normally extend much farther into the ground than just an inch. Plants that receive lightly sprinkled water may still suffer from drought stress because their roots may be surrounded with parched, hot soil. It’s much better to give plants a deep watering once a week, hydrating the ground to a soil depth of five or six inches. A light watering is likely to evaporate within a day or so, while deep watering provides plants with moisture that will stay available in the soil for several days.

A layer of mulch spread over the top of the soil helps plants out in a variety of ways. For one thing, soil covered with mulch is better able to regulate the temperature underground, and the root systems of plants growing under a layer of mulch are bound to be healthier than they would be growing in soil that does not have mulch spread on top of it. Mulching also prevents water from evaporating from the soil as quickly as it otherwise would, lowering the amount of water plants need to survive.

After reading this article, you’ve learned about how to identify when plants aren’t getting enough water and when they’re getting too much, how water moves through the soil and is put to use by your plants, and what the best techniques are for providing moisture to your garden. You’ve also learned how to quickly and easily test the soil to determine whether or not it’s time to provide your plants with another dose of water. Now that you’re armed with all this knowledge about how to best hydrate your garden, you’re ready to face whatever comes your way.