8 Factors That Determine How Often You Need to Water Your Vegetable Garden

Unlike the household chores that you can schedule—like loading the dishwasher daily, handling laundry every Saturday, or taking the trash out on Wednesdays—the frequency of watering your backyard vegetable garden relies on a variety of factors, both within and outside of your control. Since over- and under-watering can prevent your plants from reaching their full potential, it's crucial that you get it right by taking into account these eight considerations.

Natural Rainfall

Most vegetable need about 1 to 2 inches of water each week, says Robert Westerfield, consumer horticulturist with the University of Georgia. This includes both water you provide as well as rainfall, so paying attention to how the week's forecasted storms come together is your first responsibility.

"Weather will ultimately determine the frequency of watering. As a gardener, you need to be aware of the weather conditions and base the frequency of watering on temperature and rainfall," says Nancy Knauss, state master garden coordinator for Penn State Extension. This means that during some weeks, you may need to water every other day, while in rainier parts of the summer, you might not need to provide extra water at all.

Soil Drainage

Consider what type of soil you have in your garden. "Sandier soils are going to need to be watered more often, just by essence of drainage," says Westerfield. "The particle size is larger, so the water goes out." Richer, denser soils hold onto moisture longer, and adding 2 to 3 inches of mulch or compost around your plants can help retain moisture, too. "The more organic matter in your soil, the more moisture the soil will hold," says Knauss.

Watering Timing

Make sure to water at certain times of day, says Chad Massura, the CEO and founder of Rosy Soil, an eco-friendly potting mix company. Avoid watering at midday, as this is when the sun is at its peak. This will cause the water to evaporate. Plus, don't water too late in the evening, as this could lead to root rot.

Raised Beds vs. Garden Beds

A bed planted in the ground will generally lose water more slowly than a raised iteration, says Westerfield. "Raised beds drain much quicker because you're normally putting in an amended, better soil that has good rooting ability—but water goes through these soils much faster," he says. "Their advantage, which is that they drain well, is also their disadvantage—they drain so fast, you need to keep an eye on them. 1 to 2 inches a week is the guidance for a traditional in-the-ground garden. A raised bed is going to require more frequent and more inches of water, most likely."

Watering Tools

Watering methods vary, but the experts recommend avoiding overhead watering—say, from your hose or sprinkler—which soaks the plant's leaves instead of its moisture-hungry roots. "Applying water on the foliage of vegetable plants can increase the occurrence of certain fungal and bacterial diseases, especially when applied late in the day," says Knauss. "In addition, once you have a diseased plant, overhead watering can splash pathogens from the sick plant to the surrounding healthy ones."

Instead, they recommend incorporating a drip irrigation system that slowly waters the roots for a deeper, longer-lasting soak. These customizable systems are easy to build. "If you can put Legos together, you can put one of these kits together," says Westerfield. Additionally, you should allow a low-pressure stream of water to reach your plants' roots on a steady basis. They also provide homeowners with the ability to turn individual sections on or off, guaranteeing that vegetables in each section of your garden get exactly the amount of water they need.

Vegetable Varieties

Different vegetables have different water requirements. Westerfield notes that cucumbers and sweet corn are two vegetables that require plenty of moisture—but none like to get too dry. "Many vegetables are over 90 percent water—it has to come from somewhere!" says Knauss. "A consistent supply of water is essential."

Tomatoes are a prime example. "Some varieties will crack when the plants go through a dry period followed by excessive moisture," Knauss says. "Heavy rainfall or overwatering will cause the tomato to expand faster than the skin can grow, so it splits, but consistently supplying 1 to 2 inches of water on a weekly basis reduces the chance that its flesh will be damaged."

Soil Dryness

The most effective way to know when it's time to water is also the simplest: Get your hands dirty. "Feel the soil," says Westerfield. "If there's moisture detected at all—so, if you can feel a little bit in there—I'd probably hold off. You don't want to keep your plant saturated and wet all the time, but if it's really bone-dry, then that's the time to irrigate again."

Water Retention Efforts

Mulching, using water-retaining inputs, drip irrigation, and planting drought-resistant varieties will help you conserve water in your garden, which means you'll need to water less. And in turn, you'll save time and money. "Mulching helps to retain moisture in the soil by reducing evaporation and suppressing weed growth," says Massura. "Drip irrigation delivers water directly to the roots of the plants, reducing water loss due to evaporation and runoff. Planting drought-resistant varieties can also help reduce water usage." If you include inputs like biochar and compost into your soil, you'll boost soil fertility and keep water in the garden.