FRESNO, Calif. - Until six months ago, Trenton Suntrapak, of Fresno, Calif., never had seen a terrarium before. Then his girlfriend gave him one as a gift.

He marveled at the small plants growing in the open glass cylinder. About 16 inches tall, the container includes a fern in soil, small rocks, moss ground cover and even a tiny house. But as an admirer of Japanese maples, he particularly likes the Ming aralia plant, which reminds him of the Asian trees.

"It was a very unique gift," says the 34-year-old, a general manager at a local billboard company. "I thought it was cool. I've tried bonsais (in the past) and have killed them pretty fast."

So far, the plants in the terrarium have thrived under his minimal care. The terrarium sits on his dining room table, where it can get natural, indirect sunlight.

"The tree is now growing over the top" of the jar, says Suntrapak, who waters the plants once a month. "I'm pretty impressed with myself."

Terrariums were all the rage 20 to 30 years ago. Now, these miniature gardens, which are great for small living spaces, are gaining a new generation of admirers because they are easy to create and maintain.

The glass containers we know as terrariums initially were called Wardian cases. They were named for Dr. Nathaniel Bagshaw Ward, a London surgeon who was interested in plant life, according to Allen and Stella Daley's book "Making & Using Terrariums & Planters" (Blandford Press, $19.95).

Before Ward, various containers were used to transport plants and seedlings across continents, with the earliest known used during Egyptian times, according to the Daleys. In 1825, a horticulturist in Edinburgh used a glass case as a window garden, but he kept the idea to himself. Ward took the idea mainstream after he noticed a small fern and grass growing in a jar. The Wardian cases came in all shapes and sizes, often with ferns as the main plants. They became popular with the middle and upper Victorian classes.

In the 1970s and '80s, terrariums also were a common sight. "You could find them everywhere, at flea markets and floral shops," says Mary Louise Newton of Fresno, who used to own a floral business and is a Fresno County Master Gardener. "We did big business with them."

Floral designer L'Adonna Redding remembers their popularity. "I was in a (floral) shop in Santa Cruz, Calif., in the 1970s and '80s," says Redding, who now works at Lou Gentile's Flower Basket in Fresno. "We did all types. They were fun. I thought they were interesting. We haven't done them in a long, long time."

She's not sure why they faded from the spotlight. "I think they just fell out of fashion," she says.

One thing Newton has noticed about the terrariums nowadays are the glass jars. "They're more elegant containers," she says.

Her granddaughter, Mykel Newton, makes terrariums out of various-shaped glass containers. Some are rounded like a fishbowl; others can be cylindrical like Suntrapak's.

"The ones I get asked a lot about now are those apothecary jars," says Newton, 29, of Fresno. "They're so unique."

Mini gardens

Terrariums are more decorative and entail less maintenance than houseplants, says Mary Louise Newton, who will be teaching a Master Gardener class on terrariums with her granddaughter this month.

They're ideal for people with limited room, says Daniel Wilson, co-owner of Tower Garden Supply & Organic Nursery in Fresno. "We set up people with indoor gardens all the time," he says. "Terrariums are for people who are challenged for space." They're also for those who enjoy small gardens, he says.

Mykel Newton makes and sells terrariums, but you can just as easily make one, too.

"It would be a great project for kids," says Newton, who started her business, Botanic Gifts, about a year ago. "They can see what they created and watch it grow."

Find yourself an interesting clear glass jar or container; it can be open or closed.

Buy some potting soil, pebbles or rocks and horticultural charcoal, which can be found at some local nurseries.

You'll also need plants. For terrariums, tropical or moisture-loving plants work best.

These plants are among the ones Newton prefers to use in 3- or 4-inch pots. Descriptions are from the "Sunset Western Garden Book" (Sunset Books, $34.95):

n Croton: It has colorful large, variegated leaves that can be green, yellow, red, purple, pink, bronze or a combination of those colors. Contact with the leaves can cause a skin rash in some people.

n Areca palm: A small- to medium-size feather palm with graceful foliage and attractive trunk.

n Baby's tears: A fast-growing ground cover that forms a green mat.

n Maidenhair fern: A plant with fan-shaped, bright green leaves and thin, wiry and dark stems.

n Silver-nerved fittonia: A creeping plant with leaves intricately marked with white veins.

For jars with a narrow opening, Mykel Newton uses various tools, such as modified funnels for placing the soil where she wants it and long-handled back scratchers to pat down the soil.

When Newton creates her terrariums, she typically starts by laying a layer of charcoal, which acts as a filter to help keep the water from turning bad and smelly.

Next come the soil and the plants. There should be enough soil that the plants can sit with the crowns of the roots below the surface.

How you arrange the plants will depend on what appeals to you. She finishes each project by watering them.

Newton often includes pebbles, moss or both on the ground.

Decorative accessories include miniature structures such as houses or pagodas, and birds, butterflies and dragonflies. Long sticks, such as bamboo or gnarled branches, also are used.

Closed terrariums don't need to be watered as often as open ones, she says.

"You can see the soil on the side and see that it's still damp," she says. When she's not sure, "I'll drip some water and see if it drips all the way down." If it doesn't, more water isn't necessary.

Plants will need occasional pruning. "A lot of them, if they get too big, you can trim them or pinch off the tops," she says.

Suntrapak hasn't done any clipping yet, nor does he plan to. He wants to let his Ming aralia grow naturally.

"At some point, I may have to switch to a different container," he says.