Watering your plants

If you still use a lawn sprinkler to water a vegetable garden or landscape planting, or if you use an overhead watering system on hot, windy days you are wasting water. The idea of watering is to deliver an adequate amount of water to plant roots, no more, no less, and nowhere else.

There are several factors that determine how much water you need to apply and the best method of application. For starters, rainfall is a factor. No matter what plants you are watering in what type of soil, the amount of watering necessary depends on how much nature already supplies.

Another factor is the soil type. Remember that sandy soils drain quickly and that clay holds moisture for a longer period of time. These are functions of how the water moves through the soil, which affects its availability to plant roots. One inch of water applied in sandy soil will percolate down 12 inches. In good loam 1 inch of water will go down 6 to 10 inches, and in clay it will penetrate about 4 or 5 inches. Once water has filtered down beneath plant root zones it is effectively gone.

Finally, consider the plants you are watering. Some plants need much more water than others. New plants, from seeded lawns to bedding transplants and burlap-balled shrubs, require lots of frequent watering to establish their roots. On the other hand, established native plants need very little rainfall supplementation; they have naturally adapted to the area. Some plants, such as madrona, flannel bush, and western dogwood, suffer if watered in the summer.