Center for Landscape & Urban Horticulture
University of California
Center for Landscape & Urban Horticulture


Oak Trees on Golf Course
Welcome to the Center for Landscape and Urban Horticulture (CLUH), an information resource of the University of California Cooperative Extension (UC Cooperative Extension). The CLUH supports UC Cooperative Extension educational and applied research programs serving California's environmental horticulture industry. This site features science-based information on:


Please review our Mission Statement.


Low Water Landscape
For the latest science-based information on landscape water needs, please visit our pages under Landscape Water Conservation and Irrigation Management.




Cactus Garden LA Arboretum
Information is contributed by University of California Cooperative Extension scientists. All content is reviewed by these or other experts to assure it is authoritative and science-based. Featured are summaries of technical topics, fact sheets, newsletters, reports, commentary, and web links.



Calif. water use pie chart 2015
THE 9%: Landscape irrigation accounts for just 9% of water use in California, yet landscapes are under relentless attack as California confronts ongoing drought.  The facts presented here show how these attacks are misguided and that there are ways to conserve water without degrading landscape plantings.


Does the landscape you manage have a water budget or water conservation goal that seems impossible to meet? Read about Five Simple Steps for Conserving Landscape Water.



For Home Gardening information and resources, please visit the University of California Garden Web 

Raised Bed Gardening


What's new in Landscape and Urban Hort?

California Invasive Species Action Week 2023!

California Invasive Species Action Week logo.

The 10th annual California Invasive Species Action Week (CISAW) will kick off Saturday June 3rd and runs to Sunday June 11th. This week is designed to raise awareness and encourage public participation in the ongoing fight against invasive species. These...

Invasive Pest Spotlight: Emerald Ash Borer

Two adult emerald ash borers on a leaf. Photo by Stephen Ausmus, USDA.

The invasive pest spotlight focuses on emerging or potential invasive pests in California. In this issue we are covering the emerald ash borer. Emerald Ash Borer Facts The emerald ash borer is a small (roughly 3/8 to 5/8 inches long) beetle with...

Weird Worms: Land Planaria

Shovel-headed garden worm, Bipalium kewense. Photo by Whitney Cranshaw, Colorado State,

What is that weird wormlike thing in your garden? A slug? An earthworm? It may be neither—it it might be a land planarian. Land planaria are also called terrestrial flatworms and hammerhead worms. They are often colorful, such as the blue garden...

Look Out for the Jumping Worm!

A jumping worm on top of its coffee-ground like castings. Photo by M. Bertone, NCSU.

The jumping worm, Amynthas agrestis, is an invasive earthworm capable of harming native forests that has been recently reported in some areas of California. This pest devours leaf litter and other organic matter, changing soil texture and nutrient...

The “Mosquito Eater” Myth

An adult crane fly.

Lately you may have seen some large, leggy insects bumbling around on your home, bouncing off walls and ceilings. What are these? While many people call them “mosquito eaters” or “mosquito hawks,” they are actually crane flies....

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