California

California Native Plant Gardening

University of California - California Gardening Cooperative Extension

University of California – Master Gardeners Network

University of California Cooperative Extension County Offices

California Garden Clubs Inc.

Humbolt District

Siskiyou and Modoc

Cascade

Mendocino and Lake

Buttes

Golden Foothills

Sonoma, Napa Marin

Sacramento

San Francisco Bay Area

Bay Area East

Lode District

Bay Area Peninsula

Santa Clara

Yosemite

Montana De Oro District

Sequoia District

Mojave Desert

Channel Islands

San Fernando Valley

Los Angeles

Arboretum District

Los Angeles South Bay

Orange County

East Los Angeles Area

Roadrunner

San Diego Area

Composting

California Compost Quality Council

Diseases

University of California - California PestCast: Disease Model Database

Gardening in the Southwest

University of Arizona Cooperative Extension

Plants of the Southwest

General Gardening

Botany: Complete Internet Directory for Botany Subject Category List

The National Gardening Association

Insects and Their Relatives

California: University of California Integrated Pest Management

Pests of Commercial Agriculture & Horticulture

Pests of Home Landscapes

Beneficial Insect Photo Gallery

Insect Pest Identification

Pests

National Pesticide Information Center

The Environmental Protection Agency - Pesticide Information

Extension Toxicology Network - Extoxnet

The Green Book : Product Labels, MSDS, Supplemental Labels

Water

California Department of Water Resources

Weather

California Regional Weather Sever

Weeds

University of California Cooperative Extension – Weed Research