- Author: Jim Downer
California is a highly urbanized state with an expanding population. Planned landscapes and gardens are essential for Californians to maintain health promoting environments via urban landscapes. California’s urban landscapes are complex plant systems that provide essential functional, environmental, recreational, and psychological benefits for urban residents.
In 1995 landscapes covered 1.369 million acres in California, which is the most recent reliable data published. This planted area has undoubtedly grown with population increases since that time. In addition to creating beauty and health benefits, the ornamental plant and tree industry creates and supports many jobs and economic activity within the state.
The landscape industry is estimated to have a statewide economic activity well over $5 billion annually, with approximately 60% centered in Southern California. When indirect effects of tourism are included, the economic impact and importance of landscape horticulture nearly doubles. Examples of related employment numbers and their approximate memberships are: licensed landscape contractors (2,500), landscape architects (2,000), sod growers (4), arborists and city street tree managers (800+), urban water agencies (100+), along with urban forestry agencies and groups, irrigation managers and engineers, and municipal parks, planning and public works departments.
Landscapes are populated by two major categories of plants: turfgrasses, and woody ornamentals such as trees, shrubs and vines.
Turfgrass is the largest irrigated crop in the U.S. with an estimated land cover of 40.5 million acres or nearly 2% of the total area of the continental U.S.. The turfgrass industry in California is arguably the largest in the world with the economic impact from golf alone estimated to be more than $15 billion annually.
Turfgrass plays an important role in the landscape and in the lives of Californians. It is aesthetically pleasing and provides a safer, cushioned surface for sports and recreational activities. Turfgrass reduces surface temperature by transpirational cooling. It also lessens glare, noise, soil erosion, and dust thereby reducing air pollution and allergens. Turfgrass provides habitat for wildlife and reduces wildfire hazard. It has been demonstrated to be an effective bio-filter for applied pesticides and nutrients, and for pharmaceuticals and other xenobiotics (substances not normally found) in reclaimed water for irrigation.
Turfgrass also helps to remove carbon from the environment. Long-term soil testing data from Colorado golf courses were used to estimate soil C sequestration. Turf on the average golf course in their study sequestered as much as 450 kg (1000 pounds) C per acre per year, which is 1.5 to 3 times greater than soils under agricultural production.
Trees are perhaps the most emblematic and valuable individuals in landscapes. In part these valuable landscape elements provide shade, which in turn provides energy savings in shaded buildings. Trees absorb and store carbon and thus play a role in moderating global climate change. Trees also mitigate landscape noise, and provide an aesthetic environment where people live.
Unfortunately, the average life span of trees in urban landscapes is only about seven years. Though some studies have called for the survival statistics to be revised upward to 19-28 years, many urban trees still fail to establish or mature to serve their potential landscape functions. Research on sustaining trees in urban environments is more critical than ever as we rely on them for energy savings, carbon sequestration and the other benefits they add to urban landscapes. It is imperative that we find ways to extend the lifespan of these critical landscape elements in urban settings.
Jim Downer is a UCCE Farm Advisor in Ventura County. His specialties include pathology of landscape ornamental, Phytophtohora Root Rot, Mulches, Potting soils, Palm horticulture, and Arboriculture. Additional information about his research can be found here.
- Author: Chris M. Webb
The Natural Resource Conservation Service (NRCS) works extensively with the nation’s farmers and ranchers to protect soil, water, air, plant, and animal resources while meeting production goals.
Working with agricultural producers allows NRCS to promote conservation practices approximately 1.4 billion acres of the privately held land in the United States. About 92 million acres of land in our country is tended by home gardeners. In an effort to promote conservation on these lands, NRCS has partnered with other organizations to produce, Backyard Conservation: Bringing Conservation From the Countryside to Your Backyard.
This full-color and informative online resource highlights 10 conservation activities that can be used in your backyard, shared spaces, and public places too.
- Trees add beauty and so much more.
- Trees, shrubs, and other plants can provide homes and food for wildlife.
- A backyard pond will likely become the focal point for all your backyard conservation.
- Wetlands filter excess nutrients, chemicals, and sediment and provide habitat for a host of interesting creatures.
- Composting turns household wastes into valuable fertilizer.
- Mulching cools, protects, and enriches the soil.
- Apply only those nutrients the plants can use. (See our previous post on soil test kits to help you get accurate test results.)
- Terracing makes flower and vegetable gardening possible on steep slopes.
- Drip irrigation and other water conservation practices can save water and money.
- Early detection and treatment of pests means a healthier growing environment.
- Author: Chris M. Webb
Caused by the bacterium Erwinia amylovora, fire blight is a common and frequently destructive disease of pome fruit trees and related plants.
Symptoms commonly appear in spring. The first sign is usually a watery, light tan ooze that leaks from cankers. After being exposed to the air, the ooze darkens and leaves streaking on branches or trunks. Other signs of infection are petal fall, flower stem wilt, and the blackening and shriveling of flowers, shoots, and/or young fruit.
As the disease progresses, the pathogen spreads into the wood. The infected wood tissue can become sunken and cracks often develop in the bark around the infected areas.
Ideal conditions for infection, disease development and spread of the pathogen are rainy or humid weather with daytime temperatures from 75 (degree sign) F to 85 (degree sign) F.
Home Gardeners can learn more about fire blight in UC IPM’s Pests in the Gardens and Landscapes: Fire Blight publication. Subjects include: identification and damage; life cycle; and management.
Commercial growers can find fire blight information by crop on UC IPM’s Agricultural pest page.
- Author: Chris M. Webb
Produced by UC’s Statewide IPM (Integrated Pest Management) Program, Retail Nursery and Garden Center IPM News is designed to educate retail center operators and their customers on how to solve pest problems while minimizing risks to people and the environment.
The current issue features:
- Managing powdery mildew on ornamentals
- Asian citrus psyllid update
- Mushrooms and other nuisance fungi in lawns
- Preliminary report on Iron HEDTA: A natural selective herbicide
- National Pesticide Information Center: A good source of pesticide information for your customers
You may subscribe to the newsletter, read back issues, or contact authors by visiting this page of UC IPM Online.
- Author: Chris M. Webb
Part of the USDA’s Healthy Garden Workshop Series, Container Gardening and Window Boxes provides practical information to help people successfully grow plants in containers.
Readers will learn to:
- Choose the right container
- Use the right soil
- Grow the right plant for the right season
- How to water and fertilize container plants
- Choose plants that grow well in pots
- Protect plants
- And more