Maintaining Landscapes: What to do when plants are dormant
By Luis Generoso, Water Resources Manager, City of San Diego

San Diego, CA…The air is cooler and the days are shorter. These are all sure signs that summer is over and fall is here. During this time, many of your plants aren't growing as much or are starting to shed their leaves to prepare for the coming winter. This process is called dormancy. Although all plants have different schedules for dormancy - Camellias have vibrant winter blooms when most Sycamore trees have lost their leaves - every plant needs to rest sometime. Understanding this phase, and its role in a plant's lifecycle, can help you properly care for your plants and trees year-round.

"A common mistake is to equate the brown leaves of a living plant as a sign of neglect, when in reality the plant may be dormant and may in fact require less water," according to Dan Carney, Landscape Architect for the City of San Diego's Water Department. "While it is important to keep the soil moist at lower depths to promote root growth, over-watering may rot roots and kill plants."

Common lawn grasses require a fair amount of water to stay healthy and green. But they need different amounts of water as the season changes. For instance, an average lawn with commonly found sprinklers may need to be watered 60 minutes each week in July, but will need only 20 minutes per week or less in January. Some warm season grasses, such as common Bermuda grass, have their dormant period when the weather is cold. During the winter months, Bermuda grass will turn brown no matter how much water you give it. Although you want to maintain some moisture in the soil to keep the roots from drying out, you can usually turn off the sprinklers until the weather begins to warm up.

So, how do you care for these plants and grasses? Watering more may seem like the obvious solution when plants lose leaves or grass begins to brown. However, the California Urban Water Conservation Council warns that over-watering can actually cause harm to the plant's health, as well as the environment, with soil erosion, wasted water and sprinkler run-off that carries harmful pollutants to our bays and beaches.

Instead of over-watering, the key to caring for plants and grass through their resting phase is to consider other techniques to the way you care for them. These techniques include: adding mulch, which reduces evaporation and retards weed growth; clipping off leaves that are diseased; and adjusting sprinkler schedules according to seasonal changes.

To create a customized irrigation schedule for your plants and lawn, visit www.sandiego.gov/water/conservation. This website offers free access to a Landscape Watering Calculator, an easy-to-use tool that helps you estimate the right amount of water to give your garden. The calculator considers weather patterns, soil, plant, and irrigation types when creating a schedule.

The Water Conservation Program reduces water demand through promoting or providing incentives for the installation of hardware that provides permanent water savings, and by providing services and information to help San Diegans make better decisions about water use. For more information about Water Conservation, visit www.sandiego.gov/water or call 619.515.3500.