Environmental Horticulture / Environmental Science

John Karlik 661-868-6220 jfkarlik@ucdavis.edu

The goal of environmental horticulture is to preserve and enhance the environment through planting and proper cultural practices for green plants, including shade trees, shrubs, and turfgrass.  Environmental science includes preservation and enhancement of environmental quality of soil, water and air.  Kern County is a leader in the U.S. in production of rose plants for landscapes and home grounds.

Cooperative Extension provides information on turfgrass, plant selection, cultural practices, arboriculture, landscape maintenance, and pest management. 


Rose Rosette Disease Information

Rose Rosette Disease Demystified  

What is Rose Rosette Disease?

Managing Rose Rosette Disease in the Landscape


Updated  Shade and Ornamental Tree Guide for Kern County

This updated guide was revised and expanded in April 2017.  You can download the Guide here.


Horticulture Classes for Landscapes, Gardens, and Orchards

We continue to offer a series of horticulture classes in Bakersfield and Kern County.  Our goals are to conserve water, to enhance and expand green plantings, and to reduce pesticide applications. We will cover practical topics pertaining to planting and care of landscapes, orchards, and vegetable gardens, and offer plenty of time for Q&A and discussion. We welcome individuals who have little horticulture experience, as well as those who work in some aspect of horticulture.  Please feel free to contact us for information, 661-868-6200 or jfkarlik@ucdavis.edu

Fall 2019 Class - Horticulture I

We will offer our introductory Horticulture I class in Bakersfield this fall that will cover topics such as soil science, irrigation, landscape design and principles, turfgrass selection, and much more.  The class will start on August 27 and will run every Tuesday evening for 15 consecutive weeks through December 3. Sessions will start at 5:30 PM and will meet in our large conference room at 1031 South Mount Vernon Avenue. 

Registration is $75 per person and online registration is available here.

The class syllabus detailing complete session topics is available for download here.

Fall 2019 Class - Special Topics

We will offer a class in Bakersfield this fall that will cover special topics not addressed in the regular horticulture classes. The class will start on August 29 and will run every Thursday evening for 14 consecutive weeks through November 28. Sessions will start at 5:30 PM and will meet in our large conference room at 1031 South Mount Vernon Avenue. 

Registration is $75 per person and online registration is available here.

The class syllabus detailing complete session topics is available for download here.



(Additional note:Kern County does not offer the Master Gardener volunteer program at this time.  If you would like more information about that program in California, please refer to the website http://camastergardeners.ucdavis.edu/)


Horticulture Tours

I have offered several horticultural tours, and plan to continue this educational effort. Our heritage of landscape and garden design includes the rich tradition of gardens of several parts of the world, including Europe and the Mediterranean, and some of the world's most interesting and beautiful plant arrangements and collections may be found there. A number of gardens and landscapes exquisitely illustrate design principles and have withstood the test of time. These sights are well worth sharing.

The overall tour objective is to broaden participants' knowledge and appreciation for landscape design and plant selection. The tour also provides an opportunity to experience the flavor of specific countries. Group sizes have ranged from nine to twenty-six.


2020 Horticulture Tour!

May: Wales and Scotland

Download the flyer for detailed information, or you can visit the tour information and registration pages.


Past Horticulture Tours

2005 England (London environs) and France (Paris environs)

2006 Italy (Lago di Como, Florence, Rome, Pompeii)

2007 West-Central Europe (Netherlands, Berlin, Prague, Vienna)

2009 England and Scotland (northeast)

2010 Spain

2012 France and the Netherlands

2013 Ireland

2014 Scotland (northwest)

2017 Iceland

2019 Thailand and Cambodia


Research Projects

Green plants contribute volatile organic compounds (VOC) which can enter into atmospheric reactions that form ozone (a pollutant when found close to the Earth’s surface) and secondary organic aerosols. We have conducted a number of research projects pertaining to development of biogenic emission inventories, including measurement of plant VOC emission rates, leaf mass quantification, and evaluation of databases for plant species description.  This work also informs shade tree selection for mass planting programs to enhance air quality. A link to selected publications is here.

Green Scene Newsletter

The Green Scene is John Karlik's periodical publication that covers all things horticultural. Sign up today!

Green Scene July 2019
Green Scene June 2019
May 2019
Green Scene April 2019
Green Scene March 2019
37th Annual Landscape Management Seminar
Green Scene January 2019
Green Scene December 2018
Green Scene November 2018
Greenscene October 2018
Green Scene September 2018
Green Scene September 2018
Horticulture for Landscapes, Orchards, and Gardens - Special Topics Bakersfield
Green Scene August 2018 no. 2
Green Scene August 2018
Green Scene July 2018 Special Edition
Green Scene July 2018
Green Scene June 2018
Green Scene March-April 2018
Green Scene February 2018
Green Scene January 2018
Green Scene December 2017
Green Scene October 2017
Green Scene September 2017
The Green Scene August 2017
Green Scene July 2017
Green Scene June 2017
Green Scene May 2017
Green Scene March 2017
Green Scene February 2017
Green Scene January 2017
Green Scene December 2016
Green Scene November 2016
Green Scene October 2016
Green Scene September 2016
Green Scene August 2016
Green Scene July 2016
Green Scene June 2016
February 2016
Book Sale at the UC Office
Green Scene December 2015
Pruning Demonstration For Deciduous Fruit Trees
Green Scene September 2015
Green Scene Late August 2015
Green Scene August 2015
Green Scene July 2015
Green Scene July 2015
Green Scene June 2015
Green Scene April 2015
January 2015
September 2014
Centennial Celebration
June 2014
February 2014
Green Scene December 2013
Green Scene August 2013
June 2013
April 2013
March 2013
January 2013
Green Scene November 2012 Edition
Green Scene August 2012 Edition
Horticulture for Landscapes, Orchards, and Gardens Classes Offered Fall 2012
May 2012
April 2012
January 2012
November 2011
Free Pruning Demonstration
July 2011
March 2011
December 2010
August 2010
May 2010
December 2009
July 2009
July 2009 MG I & II Announcement
February 2009
July 2008
June 2008
July 2007