Q: We have a water shortage in our area. How much water do my plants really need to survive? — Pat M., Cambria
A. Water is essential for plants’ processes such as photosynthesis, nutrient uptake and transpiration, all of which directly affect a plant’s growth and development. During drought conditions when soil moisture is lacking, a plant’s growth and development are negatively affected.
Most garden plants need supplemental water when the rains have not sufficiently supplied adequate soil moisture. This is where you, the gardener, come in. Here are a few tips to keep your plants alive during a drought:
An individual garden plant needs about one inch of water each week. Then, delve deeper into various watering guides to determine how much water your larger plants and trees need. Wouldn’t it be wonderful if we could count on rainfall to provide it? But, alas, as custodians of our gardens we must provide for their minimal needs.
Water only when the soil is dry. Use your hands or a trowel to check for moisture. When soil looks or feels dry 2-3 inches down, it’s time to water shallow-rooted annuals. However, if you’re caring for larger perennial plants or trees, dig deeper to evaluate the available soil moisture as these plants are deeper rooted than flowering annuals.
Different plants have different water requirements. Shallow-rooted annuals, perennials, vegetables and newly planted landscapes will have different watering needs than larger, more established plantings. Trees and shrubs that are suited to our climate may need only occasional deep watering. The type of soil you have will dictate how often to water. For example, sandy soil dries out more
Water in the morning to give plants a chance to dry before dark. You’ll lose less moisture to evaporation and discourage fungal diseases.
Be sure to follow any local ordinances or recommendations for landscape water use.
For more information on water-wise gardening, visit the University of California Garden website, http://cagarden web.ucanr.edu/Drought_ or the landscape watering guide for San Luis Obispo County, http://www.slowaterwiselandscaping.com/Watering-Guide.
GOT A GARDENING QUESTION?
Contact the University of California Cooperative Extension Master Gardeners at 781-5939 on Mondays and Thursdays from 1 to 5 p.m. in San Luis Obispo; at 473-7190 from 10 a.m. to noon in Arroyo Grande; or at 434-4105 on Wednesdays from 9 a.m. to noon in Templeton. Visit the UCCE Master Gardeners website at http://ucanr.org/sites/mgslo or email firstname.lastname@example.org .