Is there a best time of day to water your vegetable garden? This is what we know

view of a vegetable garden

When you’ve invested time, money, and creative energy, and worked hard to create a beautiful garden, the last thing you want is to lose plants due to drought stress. Watering may seem like an intuitive task that you can’t get wrong, but that’s not true. In fact, many professional growers allow employees to only water after they’ve been thoroughly trained — and then under close supervision. There is a right way to water, and it starts with timing. 

Morning is the best time of day to water a vegetable garden. And, although it may seem like a silly thing to say, the second best time to water a vegetable garden is whenever it is dry. Let’s take a look at why morning watering is best, what happens if you water at other times of the day, and how to minimize the amount of time you spend keeping your garden hydrated.

Hydrate the plant and recharge the soil reservoir

Plants need a steady supply of water, but they use more of it in the hotter, drier afternoon hours. Morning irrigation allows plants to take a deep drink ahead of the time of greatest need. Plus, deep watering early in the day recharges the upper level soil moisture that serves as a reservoir for plants. This becomes especially apparent with restricted spaces like container gardens and raised beds. Plants transpire more water during the afternoon in order to stay cool in the sun, so they benefit from the easily accessible water that remains in the upper root zone.

Avoid damage and disease

Another reason why early watering is best is due to possible negative effects of water droplets lying on leaves. In the morning, plants generally are covered with dew, so it makes little difference if you add a bit more water to the mix. But watering in the afternoon or evening can cause or spread damage. In midday, water droplets lying on fuzzy or textured leaves (like tomatoes) can focus the sun’s rays and cause leaf burn. Late day or evening waterings increase the duration of water contact on foliage, which can cause or spread fungal diseases. So, whenever possible, stick to mornings. If secondary watering is necessary later in the day, only water the soil and keep the foliage dry.

sprinkler watering garden seedlings
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Use the right equipment

The kind of equipment you use to water the garden is as important as the time of day. Overhead sprinklers are fast, inexpensive, and easy to use, but they are not the best option. They do not water individual plants, they increase water loss to evaporation, and they wet the foliage more rather than less. For best results, consider other options like drip irrigation, a hose with a watering wand, or a watering can. These will reduce water consumption and help provide a healthier growing environment.

Water deeply but infrequently

The objective of watering is to prevent drought stress not repair it. Wide swings between wet and dry soil lead to plant stress, nutrient deficiencies, and infestation by insects and disease. Beginning at spring planting time, it is important to develop the habit of watering deeply before the soil actually dries out. Doing so will stimulate deep root development, which makes plants more resistant to the effects of the soil surface drying in hot summer weather. 

In-ground vegetable gardens need one to two inches of water per week from rainfall and irrigation combined. Containers and raised beds need more. For best results, it should be delivered via two or three waterings that are spaced evenly throughout the week. 

Effective watering takes into account variables like plant type, plant maturity (larger plants use more water), temperature, rainfall, soil type, and the type of garden (container, raised beds, or in-ground). So it’s important to become familiar with the way water flows and evaporates through your own garden, and plan accordingly.

neat rows of vegetables in a garden
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Boost efficiency with organic matter

Soils rich in organic matter use water more efficiently than those that are lacking. The two greatest contributors are compost and mulch. Apply an inch of compost annually to boost the water-holding capacity of sandy soils or improve drainage of clay. High quality compost also improves habitat for earthworms and soil-dwelling microbes that assist with nutrient cycling and disease prevention, so it’s one of the best elixirs for vegetable garden beds. A two to three inch layer of organic mulch, such as straw or wood chips, increases water efficiency by cooling the soil surface and disrupting evaporative drying.

Watering in the morning is best, but timing is only one part of the irrigation puzzle. You’ll irrigate less often and reap greater results with a well planned, thorough and consistent watering strategy. Boost soil organic matter with compost and insulate the surface with mulch. Use the right equipment to efficiently deliver water precisely where it is needed. And monitor soil and weather conditions to water deeply so that the garden never dries out.

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