Like HowStuffWorks on Facebook!

Water Tips for Gardening

A rain gauge is a helpful tool to determine how much water your plants have received.
A rain gauge is a helpful tool
to determine how much water
your plants have received.
 more pictures of garden ideas.

At least 90 percent of every plant is composed of water, which should give you some idea of how important this substance is. No plant can live without some moisture, and certain plants use it in amazing ways.

Orchids and bromeliads that live on tropical trees absorb rainwater through their foliage. Succulent plants and cacti store reservoirs of water in their swollen stem tissues so they can go for a month or more without rain. Prairie flowers such as butterfly weed store water in their fleshy taproots. And daffodils store water in their bulbs.

Without water, plants wilt and die. But too much water can be as bad for plants as not enough. If land plants are submerged in water for too long -- even if just their roots are submerged -- they may rot or drown from lack of oxygen.

Here are some tips to ensure you water your garden properly.

  • Balancing plants' water needs is like having a healthful diet. Everything should be consumed in moderation. Provide your plants with enough water for good health, but don't flood them with it.

  • Apply water in the cool of the morning or evening when the wind is calm, the sun is less hot, and water loss through evaporation is minimal.

  • Avoid watering disease-susceptible plants at night. If water sits on plant foliage for hours, it can encourage fungal diseases to attack leaves, buds, flowers, and fruit. Plants susceptible to leaf spots, fruit rots, and flower blights are best watered in the morning, when the warming sun will quickly dry off the leaves and discourage fungus development.

  • Provide an inch of water a week for many plants and lawn grasses. The idea is to keep the soil lightly moist and to prevent it from drying out completely, which would be damaging to most plants. But because plants don't always follow the rules, there are exceptions to this general guidelines: 1) Hot weather, dry sandy soil, or crowded intensive plantings or containers may make more than an inch of water a week necessary. 2) When the weather is cool, the plants are widely spaced, or the soil is heavy and moisture-retentive, less water may be required. 3) Young or new plantings require more moisture at the soil surface to help their budding roots get started. You should water lightly and more frequently to accommodate their needs. 4. Mature plantings with large root systems can be watered heavily and less often than younger plants. The moisture soaks deep into the soil and encourages the roots to thrive.

  • Set a rain gauge in an open area of the garden to learn how much water the garden receives each week. You can purchase one at a garden center or use a topless coffee can. After each rainfall, check the depth of the rain inside. A commercial rain gauge is calibrated and easy to read. To read rain levels in a coffee can, insert a ruler and note how high the water has come. Judge the need for supplemental irrigation accordingly.Rain gauges are also helpful when trying to determine when you have watered enough with an overhead sprinkler. Since some sprinklers apply water unevenly (more up close and less farther out), you could set several rain gauges around the garden and compare the amount of moisture each one collects. If the readings vary widely, move the sprinkler more frequently or invest in a more efficient model.
  • Become the master of your garden hose with help from the suggestions in the next section.

    Plants to Water in the Morning
    The following plants should only be watered in the morning, not at night:

    Want more gardening tips? Try:

    • Annuals: Plant these beauties in your garden.
    • Gardening: Discover how to garden.

    More to Explore