The courses, which include three-hour sessions for 12 weeks, are taught every fall by Penn State faculty and staff members and county extension agents.
Bonson said 12 topics are covered. Among them are plant propagation, pest management, soil composition and diagnosis, vegetable growing and composting.
On Tuesday, Karen Stoops, a master gardener, will lecture on Williamsburg-style decorations for the holiday at the Kauffman Center at Kauffman Station, Pa.
"The holiday season is a busy time for us," Lutzke said.
Home gardening is growing in popularity every year, she said. It was big in World War II when everyone had victory gardens, but by the 1950s interest had dwindled, she said. "It had a resurgence in the 1960s," she said.
"You don't have to know a lot about gardening to become a master gardener," Lutzke said. "We look for people who are interested in learning about it and who want to help other people to learn. This isn't like a garden club. You have to be able to work with the public."
"People who take the course are not supposed to do it to gain personal knowledge," Bonson said. "They are supposed to go out and teach others about horticulture."
Certified master gardeners like Lutzke go out into the community to lecture on gardening, plant two demonstration gardens on land at the extension office, go into elementary classrooms to talk to students, conduct public workshops and offer technical help to on gardening and related problems.
During growing season, volunteers also run a telephone hot line at 1-717-263-9226, Bonson said.
"Last year the 36 master gardeners here donated more than 4,000 hours teaching people horticulture," she said. The program has more projects that the master gardeners can handle, she said.
Lutzke has been gardening since she learned she could actually grow things. "Of course I'm much better at it now. It's the whole process of life and death, of starting seeds and growing things, especially things you can't buy. This year I grew Peruvian tomatoes."
Lutzke said she doesn't use pesticides in her garden. "If you have really good soil with adequate nutrients and water, you don't usually have trouble with pests," she said. "It's like your own body. If you take care of yourself, your body's immune system will keep you healthy."
Lutzke said a first, important step in any garden is having the soil tested. "Everybody avoids that step. It tells you what your soil is lacking and how to amend it," she said. "If you have good soil you can grow anything."