Responsible Gardening: Calculating Plant Watering Needs

Posted on — By Dylan Cabico

Calculating Plant Watering Needs

In order to take care of your garden, you must first acclimate yourself to what exactly your garden needs to thrive and flourish. Four things are required for plants to grow healthy: plenty of sun, nutritious soil, oxygen, and water. Here in the Mojave Desert, only one item on that list is something that is considered scarce; can you guess what it is? Correct! The answer is water!

Keeping it Green

Knowing how much water your plant needs in order to live is important. Just as plants can die of being under-watered, they can easily die by being over-watered. ­­Signs of plants being over-watered are: moist soil, pale yellow leaves, or soft drooping leaves that are still attached. What’s happening is that plants use their roots to absorb nutrients, oxygen, and water. If there is too much water, the roots will drown and not be able to receive the oxygen it wants.

So, how does one know the exact threshold of water their plant needs in order to live?

In order to find that balance I used a Landscape Water Requirement Calculator created by the University of California Cooperative Extension. The criteria you must know beforehand are the canopy diameter in feet of your plant and the average ET inches per day. What exactly is the average ET o inches per day you ask? ET stands for Evapotranspiration. That mouthful of a word means tiny amounts of water from the plant and soil are evaporated into the atmosphere. When researching just how much water the plants at Sinatra Living required, I had to find out how many inches of water were lost in Las Vegas due to ET.

A helpful source of information came in the form of a paper entitled Managing Landscape Water Use in the Las Vegas Valley: Potential ET. From there it was fairly straightforward and I could then plug in numbers to help me better understand how much water the plants required. Killing plants due to overwatering are more common than one may think. By following these instructions, you will become one step closer to having that gorgeous garden of the neighborhood!