Watering Your Veggie Garden

Hose watering is best done on container or individual plants so to not waste water.

It seems like this technique should be as obvious and easy as picking a tomato, but how you water your vegetables can influence the size and quality of the harvest. Besides the soil, water is the most essential element to plants. Improper watering can cause plants to be dwarf, stunted, and produce poorly. It's not just drought conditions that can cause a problem. Too much water can be as harmful as too little. Too much water can squeeze air out of the soil, causing poor plant growth.

The old rule of thumb was to give your plants one inch of water a week. That's a good general guide, but the reality will depend on weather and your soil. Sandy soil and soils low in organic matter tend to dry out faster and will require more frequent watering. Clay soils and soils high in organic matter hold onto the water longer and require less frequent watering.

It's important to know the most critical time in a vegetable's growth to water. Mulching helps reduce the need for extra water.

It's always better to water infrequently and deeply than frequently and shallowly. Frequent light waterings only moisten the top few inches of the soil. The roots will stay where the water is and when dry conditions occur, the plant is more likely to suffer water stress due to the shallow roots. Deep waterings send water down 6 inches to a foot into the soil and the roots will follow. These plants will be more likely to survive a bout of drought.

When To Water?

You'll know your plants need water by looking at the leaves and soil. Wilting plants and dry soil are a sure sign of water stress. However, don't just look at the wilting leaves. If the soil is moist, the wilting may be due to other problems such as disease or overwatering. Some plants, such as eggplant, will naturally wilt during hot periods but recover when the temperatures cool. They may not need watering.

If the plants aren't indicating it's time to water, the soil will. You can also stick your finger in the soil. If you dig down 3 to 4 inches into the soil and it's still dry, it's time to water.

So, while it's important to keep plants properly watered all season long, there are critical times of the growing season to water. Here's a chart adapted from the book, Vegetable Gardening for Dummies (2009, Wiley), showing the most critical times to water your produce.

The Harvest Table

Vegetable	Critical Watering Period
Bush bean	When flowering and forming pods
Broccoli	When forming a head
Brussels Sprouts	When forming sprouts
Cabbage	When forming a head
Carrot	When forming roots
Cauliflower	When forming a head
Sweet corn	When silking, tasseling, forming ears
Cucumber	When flowering and developing fruit
Eggplant	From flowering to harvest
Lettuce	When true leaves form
Melon	During fruit set and early development
Onion	During bulb enlargement
Pea	When flowering and during seed enlargement
Pepper	From flowering until harvest
Potato	When tubers set and enlarge
Pumpkin	When fruits form
Radish	When forming roots
Spinach	When true leaves form
Summer squash	When forming buds and flowering
Swiss chard	When true leaves form
Tomato	From flowering until harvest
Turnip	When forming roots

Ways to Water

Avoid using overhead sprinklers if you can. They tend to waste more water than soaker hoses and drip irrigation lines.

Not only is the timing of your watering important, how you water makes a difference too. Depending on your area and the season, there may be watering restrictions in place or water may be very expensive. Using efficient watering systems not only will be better for the plant, it can save water and money for you.

Here are some of the common ways to water your garden, with advantages and disadvantages of each. The automated systems described below are best used with a timer that will turn your watering device on and off so you don't have to remember.

Hand water — This is probably the most common way gardeners water. While it is one of the easiest watering methods, it's sometimes not the most effective or efficient. It's common to waste water sprinkling pathways. Also, the water may be distributed unevenly. Hand watering with a hose or watering can is best used on containers and individual plants. In fact, the most efficient way to hand water is to create a basin or furrow near the individual plant or row and fill it with water. Let it sink in, then move to the next basin. This works particularly well early in the season, when plants are small.
Sprinklers — This is probably even easier than hand watering because all you do is set up the overhead sprinkler and let it run for a designated period of time. While the water soaks into the ground well, the down side is you'll be wasting lots of water in the process watering pathways. Also, this type of watering should be done in the morning so the leaves dry before evening. Wet leaves at night are an open invitation to disease.
Soaker Hoses — A more efficient way to water is to lay soaker hoses around plants and along rows. These low-flow hoses weep water into the soil around plant roots and are less likely to waste water. They work best laid under plastic mulch used around warm season crops, such as tomatoes and melons. Soaker hoses also work best on flat ground to evenly distribute the water.

Soaker hoses concentrate water near roots where the plant needs it the most.

Drip irrigation — Drip irrigation is similar to soaker hoses in that you'll be focusing the placement of water near the plant roots. However, it's even more efficient and wastes even less water. The downside is the cost and maintenance. There are more parts to the drip irrigation system that needs to be checked frequently to open clogs and fix leaks. Plus, drip irrigation is more expensive than any other watering system.
Mulch — Though not a watering system per se, mulch is critical to conserving soil moisture and keeping weeds away. Organic mulches such as straw, pine straw, bark mulch and untreated grass clippings will reduce the amount of watering and weeding you'll have to do during the growing season. Weeds are important to control because they will compete with your plants for water. Plastic mulches conserve moisture too, but work best with a soaker hose or drip irrigation lines running under them to keep the plant roots moist.

National Gardening Association

"When You Garden, You Grow"

Watering Your Veggie Garden

When To Water?

The Harvest Table

Ways to Water

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