Plant Health

UC Master Gardeners of Amador County's ClassesUC Master Gardeners offer free classes on various gardening topics throughout the year.  Check our calendar for upcoming classes each month. 2025 Calendar of EventsFor more information contact the Master Gardeners 10am to noon,…

Master Gardeners are trained educational outreach volunteers with the University of California Cooperative Extension program; they provide practical scientific horticulture and gardening information to gardeners in their communities across California.

The application process for the UC Master Gardeners of Merced County's 2026 Training Class is now open. Any Merced County adult resident with an interest in horticulture (plants, lawns, trees, vegetables and more) and public service are encouraged to apply for the Master Gardener Program.

Send us an email anrmgmerced@ucanr.edu Visit our information booth at the Merced Farmer's Market on the first and third of most Saturdays from 8-11am (March- October). Attend one of our monthly community workshops. Click here to view the event calendar. Subscribe to our public newsletter.

Gardening extremes occur when unexpected weather conditions challenge plant growth and survival. Frost, heat, floods, wind, and drought are all environmental changes that can result in plant injury. Plant damage can be sudden and severe or it may occur over time.

Frost injures plants by causing ice crystals to form in plant cells. This makes water unavailable to plant tissues and disrupts the movement of fluids. Frost-damaged leaves appear water-soaked, shrivel, and turn dark brown or black.

Wilted, drooping leaves are signs of heat stress in plants. Photo credit: Pikist.com Plants are sensitive to both air and soil surface temperatures. Temperatures ranging from 60 to 85F are optimum for plant growth and development.

Richard Bell, Unsplash Most landscape plants will survive a few days of flooding. Photo credit: Iowa State University Plant roots need air too. Good garden soil contains a network of pore spaces filled with water and air. Both are necessary for healthy roots and beneficial soil-dwelling organisms.

Plants can dry out quickly when exposed to constant wind. Photo credit: UC Regents The force, direction, and persistence of the wind determine the type of damage plants may suffer. Most damage occurs with winds above 30 miles per hour.