Landscaping plants have different water needs. The water requirement of each plant in your landscaping can be determined by gathering information about the plant and then comparing it to the amount of water needed by the cool-season grass growing in your climate zone.
Healthy, living soil is full of oxygen, water, and life to support your plants. This is the food your plants need to consume for good health. Creating healthy soil in layers is referred to as soil sheet mulching, or “soil lasagna.” It isn’t too much different than cooking a pan of lasagna in your kitchen.
How much mulch does your landscaping plan need? To develop your mulch master plan and answer this question, you first need to understand the job it will perform in different areas of your watersmart landscaping plan.
How much mulch does your landscaping plan need? To develop your mulch master plan and answer this question, you first need to understand the job it will perform in different areas of your watersmart landscaping plan.
Master Tip: Keep mulch one to six inches away from plant stems. When mulch crowds them, it can cause plants to rot due to moisture.
How much mulch do you need? First, decide how it will be used in your sustainable landscaping. Photo: San Diego County Water Authority
For accurate results, check these numbers:
Take your square footage, multiplied by mulch thickness, and divide this number by 12. The result is the amount of mulch you need in cubic feet.
Example: 891 square feet of land, multiplied by one inch of mulch, divided by 12 = 74.25 cubic feet of mulch.
Inorganic mulches don’t decompose to feed your soil microbes and keep your plants and garden healthy and thriving. There are also some organic mulches containing dyes or other chemicals. Others such as shredded redwood take a very long time to break down.
Master Tip – These are the types of mulches you should use only in areas without plants:
This article is part of a year-long series inspired by the 71-page Sustainable Landscapes Program guidebook. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.
Knowing how to use a soil probe as an important soil management tool will support your effort to create a healthy, thriving landscape full of beautiful plants.
You need to first know as much as possible about your soil to understand your irrigation needs. Irrigation is critical to keep your landscaping green and growing. But more isn’t better. One way to easily gauge your landscape’s needs is to use the Jar Test.
Another helpful tool is a soil probe. A soil probe lets you determine a lot more information about the soils in your landscaping. It will give you information about whether your irrigation is successfully reaching the roots of your plants, or even if it soaks in too deep past the reach of plant roots.
If you don’t understand your individual soil profile, you can’t plan effective irrigation. When there is variability in the conditions across your landscape, you may have different types of soils from one area to another or from a surface layer of soil to a deeper layer.
A good soil probe will help you figure out when your irrigation water has reached the right depth for the plants in your landscaping. It is a simple process with the right tools.
Use a soil probe to test how well irrigation dispenses into your landscape. Photo: University of Florida/Creative Commons
When your soil is moist, a soil probe should go into the ground easily, without a lot of effort. Your soil probe will stop when it hits hard, dry dirt, and won’t go further. But your soil probe could also be hitting rock, so you may want to reposition it just a few inches away and try again.
If you are confident you’ve hit only dry soil, put your fingers around the probe at the soil surface, and pull it out. Measure the depth in inches to learn how deep your irrigation will penetrate into the soil.
To properly irrigate your plants, understand the depth of their roots. Trees send their roots much deeper into the soil than shrubs, and shrubs have deeper roots than bedding plants like annual and perennial flowers or vegetables.
Most plants will do fine as long as the top foot of soil (12 inches) is filled with water when you irrigate. Shrubs should be irrigated to a depth of two feet (24 inches), and trees irrigated to a depth of three feet (36 inches).
You can purchase a soil probe at any general hardware store or gardening center. A basic soil probe costs between $30 and $80, but there are high-tech probes costing up to $300.
To learn more about your soil, sign up for Soil & Site Assessments virtual workshop.
This article is part of a year-long series inspired by the 71-page Sustainable Landscapes Program guidebook. The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at WaterSmartSD.org.
Making smart decisions about your landscape design and your plant choices relies in large part on your climate zone. San Diego County’s six different climate zones vary in their average conditions. By choosing wisely, you can minimize the need for artificial irrigation and still create a beautiful, sustainable landscape. The California Irrigation Management Information System divides San Diego County into these six climate zones: Coastal, Coastal Inland, Upland Central, Transition, Mountain, and Desert.
The Water News Network is San Diego County’s source for water news and information.
