Water Use Classification of Landscape Species (WUCOLS):
The Water Use Classification of Landscape Species (WUCOLS) is a system used in California to categorize plants based on their water needs and tolerance. It’s primarily aimed at assisting landscape professionals, designers, and homeowners in selecting plants that are well-suited to the region’s climate and water availability.
WUCOLS categorizes plants into several different water use classifications, ranging from very low to very high water use. These classifications help in making informed decisions about which plants to use in landscaping to promote water conservation and sustainability.
Here are the main water use classifications used in WUCOLS:
Very Low: Plants in this category require little to no supplemental irrigation once established.
Low: Plants in this category require occasional supplemental irrigation, particularly during extended dry periods.
Moderate: Plants in this category require regular supplemental irrigation to maintain healthy growth.
High: Plants in this category require frequent supplemental irrigation to thrive.
Very High: Plants in this category have high water needs and may require constant irrigation to survive.
Number CIMIS | WUCOLS | Region Sunset climate zones* | ET0 zones** | Representative Cities |
1 | North-Central Coastal | 14, 15, 16, 17 | 1, 2, 3, 4, 6, 8 | Healdsburg, Napa, San Jose, Salinas, San Francisco, San Luis Obispo |
2 | Central Valley | 8, 9, 14 | 12, 14, 15, 16 | Auburn, Bakersfield, Chico, Fresno, Modesto, Sacramento |
3 | South Coastal | 22, 23, 24 | 1, 2, 4, 6 | Irvine, Los Angeles, Santa Barbara, Ventura, Vista |
4 | South Inland | 18, 19, 20, 21 | 9 | Corona, Escondido, Pasadena, Riverside, San Bernardino, Santa Paula |
5 | High and Intermediate Desert | 11 | 14, 17 | Apple Valley, Barstow, Bishop, Lancaster, Lone Pine, Tehachapi |
6 | Low Desert | 13 | 18 | Borrego Springs, Blythe, Death Valley, El Centro, Needles, Palm Springs |
More details about WUCOLS can be found here : https://ccuh.ucdavis.edu/wucols