How and When to Water Your Garden

We’ve all seen a plant that lacks water. The leaves wilt and turn brown. Stems dry up and eventually collapse. Along with light, air and nutrients, plants need water to grow and thrive.

Water: the lifeblood of your garden

Plants absorb water through their roots and use it during photosynthesis to make their own food. Water also acts as a conduit for nutrients that travel from the soil to the plant’s roots, stems and leaves.

Underwatering stresses plants, deprives them of nutrients and makes them more susceptible to diseases and pests.

Underwatering stresses plants, deprives them of nutrients and makes them more susceptible to diseases and pests. Overwatering causes leaves to turn yellow and fall off. Roots rot, leaving the plant untethered in the soil.

Delivering the right amount of water to your garden takes practice and a little know-how, but it’s easy to do once you’ve set up your routine.

Garden watering basics

How much water does my garden need?

Most outdoor plants need one inch of water per week (0.623 gallons per square foot). But what does that mean for your garden?

According to the University of California, a standard 4’ x 8’ raised bed needs 20 gallons of water per week (32 square feet x 0.623 gallons). In-ground gardens will use slightly less, but both will be affected by the amount of evaporation occurring in your area on a given day.

The best way to see if your garden is getting enough water is by placing an empty bowl or can next to your plants before you water. Measure the volume in the can after your watering cycle is complete. Did your plants get the one inch required?

Does soil type affect how much I should water my garden?

Soil type will affect the amount of water your plants receive. That’s because some soil types are better at retaining and delivering water directly to your plants.

The ideal garden has loamy soil–a combination of clay, silt and sand particles–along with organic matter.

While clay soil tends to hold water near the surface, sandy soil tends to drain water quickly away from plant roots. The ideal garden has loamy soil. Loam is a combination of silt, clay and sand particles, along with organic matter. It resists drying out during hot spells, but doesn’t get waterlogged when the rain comes. If you have loamy soil in your garden, you’ll water less and have better overall growth.

If you don’t have loamy soil, you can add composted kitchen scraps, manure or yard waste. Composted organic matter of almost any kind will increase your soil’s ability to retain water. Over time, this will help transform your garden soil into loam.

What’s the best way to water a garden?

Depending on your garden’s location, orientation and size, there are different ways to water.

• Drip irrigation is the most effective solution for irrigating a garden, because it delivers water right where your plants need it–at soil level–while minimizing evaporation. However, drip irrigation doesn’t always make sense in smaller gardens, since it costs more to set up. Read more about drip irrigation.
• Soaker hoses are a great option for smaller gardens. They set up instantly and cost little. Like drip irrigation, soaker hoses deliver their water at soil level. They’re less precise than drip systems, but they do come in a variety of lengths and diameters to meet a variety of needs.
• Sprinklers are less effective when it comes to watering gardens, since they tend to lose more water to evaporation and overspray. Rather than delivering water at ground level, sprinklers spray it over a broad area. More water is wasted, instead of targeting your plants. Sprinklers can also spread disease, because they wet a plant’s leaves along with the soil. Sprinklers make the most sense when establishing a new lawn or cover crop.
• Hand watering is precise and has many benefits. Of course, it takes longer and may not be practical for larger spaces, but it does bring you into regular, close contact with your plants. In this way, you can troubleshoot small issues before they become something bigger.

Related: Drip Irrigation vs. Soaker Hoses: Which is Better for Your Garden?

What’s the best time of day to water?

Water as early in the morning as possible. This helps reduce water lost to evaporation, since mornings are the coolest part of the day. If you can automate your watering system, irrigating during the night is even better, particularly on hot days.

Special circumstances

Vegetables vs. lawns vs. shrubs and fruit trees

While most plants do very well with an inch of water each week, some will have more specific needs. Here are some of the most common considerations:

• Fruit trees do best with deep, weekly or bi-weekly watering depending on the season and the age/size of the tree. When planting out a young fruit tree, water two to three times per week until the plant gets established. Reduce to a deep, weekly watering for the first two years. Once fully established, watering every other week will usually be enough to sustain your tree.
• Vegetable seedlings will need daily or twice-daily waterings when in pots and when first transplanted. Once established in the garden, a twice-weekly watering, adding up to one inch per week, will do.
• Potted plants, and plants in containers and planter boxes, dry out more quickly than in-ground beds. Water daily, particularly when your plants have been exposed to high temperatures.

What about during heat waves?

Watering during a heat wave should be done as early in the morning as possible. This will prevent sunscald on plant leaves and minimize evaporation. If possible, use drip irrigation during the coolest part of the day (or night).

How to reduce your garden's watering needs

While getting your routine right is important, you can also reduce your garden’s watering needs by taking the following steps.

• Mulch your garden. Applying mulch to the soil surface after planting helps keep soil cool and prevents evaporation. There are so many great mulches available, from straw to compost.
• Maintain good organic matter levels. Soil rich in organic matter retains moisture. It also contains more nutrients per square inch. Apply compost once or twice a year to help maintain organic levels.
• Practice no-till gardening. Every time you churn up the soil, you release moisture to the air from deep down in the soil. Instead, try not to disturb the soil at all. Plant cover crops in the fall, then mow them down come springtime and apply mulch and compost. No-till methods also increase your soil’s ability to store carbon. Raised row gardening is one excellent no-till method.
• Automate your watering system or use a timer. If you have a large garden, consider adding an automatic watering system attached to drip irrigation. This kind of system will save you water every time you turn it on. You can even find solar-powered automations.

  If you can’t fully automate your system, consider adding a simple water timer to prevent waste. Water timers work well with soaker hoses, sprinklers and more.

• Don’t water when it rains! This may sound ridiculous, but if you’ve automated your watering system, don’t forget to turn it off on rainy days.

Use water-saving tools. A number of inexpensive, water conservation tools are on the market to help gardeners save water and give their plants what they need. We’ve detailed some of them below.

Related: 10 Water-Saving Garden Products You Should Know About

Rain barrels are just one effective water-conserving garden tool.

Tools that can help conserve water

• Soil moisture meter: Insert a moisture meter probe into your garden to test how much water is available to your plants. Adjust your watering routine as needed.
• Rain gauge: Find out exactly how much water your plants are receiving using a digital or analog model.
• Watering wand: Reach those hard-to-water places using this ‘arm extender.’ Watering wands usually have multiple spray settings for different plant needs. Some even mimic rainfall.
• Rain barrels: Save water from a downspout or rooftop for later use. Rain barrels come in a variety of shapes and sizes.

Ultimately your plants will let you know if you’re not watering enough (or too much). Thriving plants are robust, tall, green and lush. Inspect them regularly and adjust your routine as needed. Your plants will thank you!