Mary Jones' love of gardening has transformed Westward Ho's old inner courtyard.

In the 1950s, Mary Jones had lunch at the Westward Ho when it was the spot to go to in Phoenix. She was a teacher in Wickenburg and took the train to Phoenix on weekends. Today, she lives at the 350-room former hotel, which has been converted into low-cost housing for senior citizens and the disabled. ''I never expected to live here,'' Jones said. She never expected to be the hotel's premier gardener, either, but Jones, 83, has been instrumental in restoring the garden areas of the Westward Ho's inner courtyard.

''When I came here in 1981, this patio had nothing in it except two orange trees and a palm tree,'' Jones said. ''It was devastating. The pool was filled with trash.''

That's when Jones got mad and had it cleaned up. She also established a lawn and began planting in all the non-cement areas.

She had little money to buy new plants; many of the early offerings came from other residents.

''People would get plants for Christmas, then give me the bulbs and I'd stick them in the ground.''

She revived her share of ''dead'' plants, too. ''I'd stick their dead plants in the ground, cut them back and they'd take off again.''

Seven years after she started her revegetation project, the old hotel's courtyard has been transformed into a minibotanical garden.

Flowers hang over Mexican tile; large-trunked San Diego red bougainvillea climb inner walls; bright lantana bushes attract butterflies; massive honeysuckles and aloe vera with shoots of tubular, salmon-colored flowers pull in hummingbirds.

''We have a hundred rosebushes now,'' Jones said. Including the normally touchy sterling-silver rose.

''We have a good exposure here with all the afternoon shade from the apartments,'' Jones said.

Blue hibiscus, amaryllis, red cannas, herbs and purple wandering Jews also grow there.

Flowering cactuses thrive in poolside containers.

At one time, Jones tried a vegetable garden but ran into some unexpected problems from overzealous residents who plucked tomatoes off the plants before they were ripe.

''They stole me blind,'' Jones said. ''I got so mad, one day I pulled them all up.''

Kim Wagner, activity coordinator at the Westward Ho, has been impressed with Jones' determination. ''She does a great job,'' Wagner said. ''She's turned it around and keeps it going by having bake sales.''

Residents who would like to participate but are physically limited also chip in what they can when they can.

''Mary has also helped me with my roses at home,'' Wagner said. ''She's helped me get rid of my aphids.''

Jones said her knowledge of gardening comes from reading about gardening and doing it.

She also gardens for the exercise. ''It's better than aerobic dancing.''

Jones said other residents also volunteer to work in the gardens, but many are unable to participate because of heart trouble or severe arthritis.

Most, however, including a man named Eric, are appreciative of Jones' efforts. Eric, 90, wears a T-shirt that tells the world he loves Sun City. Jones calls him ''their polar bear.''

''We call him that because he swims in the pool when it's ice-cold. He runs up and down the fire escape two steps at a time, too. I said, 'Eric, you're going to drop dead doing that.' And he said, 'No, that's what keeps me alive.' ''

Although Jones said she is able to manage, she could still use some help pruning her roses and shrubs. ''I never know if I'm pruning the roses correctly,'' Jones said. ''And pruning the shrubs takes a little more strength than the residents here have.''