Cass Turnbull displays a copy of her book, “Guide to Pruning: What, When, Where & How to Prune for a Beautiful Garden.”

Cass Turnbull, founder of PlantAmnesty, a non-profit organization that aims to end the “senseless torture and mutilation of shrubs and trees” by establishing quality standards in pruning, shared tips with the Garden Club of Los Altos Feb. 28.

Turnbull, a gardener, landscaper and arborist, began her career nearly 20 years ago in Seattle, armed with a sense of mission and a sense of humor. She used every medium available - press, television, videos and books - to goad, shame and educate the city. “It’s amazing,” she said, “how the press loves a competition for the ugliest tree on the block or the worst piece of pruning on X street.”

Tailoring her program to the Los Altos audience, Turnbull talked of pruning local shrubs and trees, including azaleas, camellias, maples and nandinas. “Pruning is always the same, just adjusted to locale,” she said.

No plant requires pruning, according to Turnbull. Plants grow naturally, and genus, species and age determine their ultimate size. It is the gardener who wants to prune plants to a particular shape - and 80 percent of what the pruner does is bad for the plant, she said.

Turnbull used slides, diagrams and humorous asides to illustrate her points about indiscriminate shearing and hacking. She told the club to visualize the desired result and offered tips: get inside the bush, cut out the deadwood and work from the bottom.

The Garden Club of Los Altos meets the fourth Tuesday of each month at Christ Episcopal Church, 1040 Border Road, Los Altos. For more information, call Linda Caprini at 363-4377.