All plants need water. Correct irrigation frequency and technique are among the most important factors for a successful garden, and yet improper watering may be the most common reason why plants die. Increase the health and beauty of your landscape by watering your plants at the right time and with the right method and frequency.
The Best Time of Day for Watering
The early morning is the best time to water a garden. The earlier in the morning that you head out to your garden, the better. Morning irrigation gives plants the crucial moisture they need to get through the hottest parts of the day. Watering plants in early morning also conserves the most water. That's because less moisture is lost through heat evaporation and mornings tend to be the least windy part of the day.
If your schedule doesn't allow time to water in early morning, then water in late afternoon or early evening.
If you water plants in late afternoon or early evening, do so only at the plants' bases. Avoid any form of overhead irrigation, and do not get the plants' leaves wet. If foliage gets wet in the evening, it typically stays wet all night. Chronically wet leaves have a higher risk of contracting various plant diseases.
The Best Watering Depth
When watering plants in early morning, late afternoon or evening, use enough irrigation to moisten the soil to a depth of at least 12 inches. Deep soaking encourages all plants to extend their roots deeper in the soil, which enhances plant health and strength.
In contrast, shallow watering encourages plants to keep their roots closer to the soil surface. That situation weakens the plants and leaves them more susceptible to various problems, such as heat stress and toppling.
The Best Watering Frequency
Watering just once each week is typically enough for most plants that are in the ground. In an effort to conserve water, many municipalities also restrict residents to watering only once every seven days.
Differences in climate, soil types and natural rainfall can affect the watering needs of your garden. For example, sandy soil dries out faster than heavy loam soil. Aim for watering once each week, but check the soil's moisture level frequently. Water the in-ground plants again whenever the soil has dried out to a depth of 4 inches.
Because every plant is different, the once-a-week general rule may not always apply. Water more frequently whenever your plants show signs of drought stress. Symptoms include:
- Leaves curling inward.
- Widespread wilting.
- Yellowing of foliage.
- Dying stems or twigs on a plant's outermost edges.
Container gardens are the exception to the once-a-week watering rule. Because all sides of containers are exposed to wind and the sun's heat, containers' potting soil typically dries out rapidly. Water potted plants whenever the top 2 inches of their potting soil has dried out. In many cases, potted plants need to be watered once or even twice per day.
The Best Methods of Soil Moisture Conservation
Water is an important resource that can become depleted in some areas. Do your part to conserve soil moisture. It's good for the planet, your plants and your utility bill. Compost and mulch are two key components for soil moisture conservation in a garden.
You can make compost at home or buy it from sources such as a garden store or plant nursery. Compost enhances soil nutrient levels, helps the soil soak up and retain moisture and improves soil aeration. Before planting a garden, mix 2 to 3 inches of compost with the top 8 to 10 inches of soil. Repeat that task at the start of every growing season.
Mulching adds a layer of organic matter to the soil surface. It helps keep out weeds that would otherwise compete with desirable plants for soil moisture and soil nutrients, and it helps retain soil moisture by shielding the soil surface from wind and sunlight. Maintain a 2- to 3-inch layer of mulch around your garden plants, but keep the mulch away from the plants' stems and leaves to prevent plant diseases.
Options for mulch material include:
- Shredded leaves.
- Certified weed-free straw.
- Bark chips.
- Shredded bark.