Watering plants is part art and part science. While many people realize the importance of water for plants in the hot, dry days of summer, they may not realize that it is possible to overwater plants. In fact too much water can be just as damaging as too little. For your plants to thrive, it is important to strike a balance when you water the plants.
Too much water is harmful because plants need oxygen to survive. Normally this oxygen is located in small pockets in the soil. If a plant receives too much water, it fills this space that normally holds oxygen. Without oxygen, the plant will eventually die.
Too little water can kill your plants as well. Plants lose a good deal of water every day. If that water is not replaced, it is impossible for the plant to survive. Plants lose water when it evaporates from the surface of the soil and through a process called transpiration. Transpiration occurs when water is lost through a plant’s leaves.
Transpiration is a necessary life function for plants. If they cannot release water through their leaves, they will not grow strong and healthy. It is important to provide your plant with enough water so that it can effectively use the transpiration process.
There is no easy answer to how much water is the perfect amount. Many of the symptoms of too much water are identical to the symptoms of too little water. If your plant experiences any of these symptoms, you will have to do additional detective work to determine whether your plant needs more or less water. Symptoms that your watering schedule is not working are wilting, yellowing, loss of leaves and dry foliage. Both overwatering and underwatering will eventually kill a plant.
Even if your plant looks healthy, it may still suffer from the effects of too much or too little water. Stress from over- or underwatering will make the plant more susceptible to damage from disease and insects and decrease its level of cold weather hardiness. It is important to experiment with your plants to determine the best level of water for each.
If you have clay soil, water will remain in the soil for a longer period of time. This soil holds moisture in, so it is easy to overwater plants in an area with clay soil. Sandy soil drains quickly. If your garden has sandy soil, you may find that the plants need frequent, thorough watering to survive. Water drains through sandy soil quickly, leaving it out of reach of the plant’s roots.
Adding organic matter, such as compost, to your soil can make clay soil drain quicker and sandy soil drain more slowly. You should also get in the habit of scrapping the soil aside with a trowel after watering to see how deep the moisture penetrated. Plants generally prefer a thorough soaking and then time to partially dry out before another watering. Light, daily watering is best for container gardens, not traditional flower or vegetable gardens.