More than two decades ago, after their grown-up kids had - yet again - overwatered or underwatered the houseplants while Rita and Rich Hojnowski were away on vacation, Rita got religion.

To heck with those dried-up, bloated - and boring - houseplants. She would grow succulents instead. They're freaky and fun and, best of all, need little water.

"If nobody waters them, nothing happens," says Hojnowski, a retired medical technician in Blackwood.

Like most gardeners in the throes of plant infatuation, Hojnowski downplays the depth of her involvement with these water-storing geniuses, things like sedum, snake plant and sempervivum, agave, cactus and ice plant.

First, she confesses to having "a lot" of succulents, then "750 inside and a few more outside." Turns out she's pushing 1,000, down from a onetime high of 1,500.

You'd never guess from the front of the house, which features grass and uniform rows of purple and red annuals. But in the back, her succulents reach across the greenhouse aisle like vines in a jungle. They weave a chunky tapestry in the perennial beds and around the gazebo.

Even the humble woodshed near the pool is topped with a succulent green roof. In late June, it was a rainbow crew cut up there; Hojnowski, a member of the Philadelphia Cactus and Succulent Society, spends many an hour standing on concrete blocks fussing over it.

"This is my main interest now," she says, indulging in understatement once again.

Must be contagious, because succulents - both the tender ones that come inside for the winter in our region and the hardy ones that can take frost - seem more popular than ever. That's certainly true at the Philadelphia Flower Show, where succulent entries in competitive classes jumped from 357 in 2001 to 1,356 this year.

And it's true at garden centers like Marano's, a fixture in Fort Washington for 48 years, says Joe Marano Jr., whose mother, Joanne, won many flower show awards for her succulents. He sells and grows lots of varieties, including the darkly dramatic burgundy-black Aeonium arboreum 'Zwartkop,' the chalky blue Senecio and the rosy-gold, chubby-cheeked Sedum nussbaumerianum.

Succulents are adored for their texture and architecture. They can be spiked or matted, shiny or frosted, hairy, prickly, velvety or webbed. Some curl into tiny, elegant rosettes or huge paddles; others form wide fans, fat spears, or sharp pirate swords.

The colors are memorable, too: chartreuse, pink and rust, cream and sage, magenta and pearly blue-gray. And the flowers - though mostly small, uncomplicated, and anathema to fans of "flower flash" - are a bright blink in the sunshine, nonetheless.

"Succulents are just fun. They're different. They look like aliens," Marano says, noting that the growing interest in drought-tolerant plants and water-wise, xeriscape gardens has fueled the public appetite for succulents.

"And people lead such busy lives," he adds. "They don't have time to take care of containers. They want to put them on the patio. No fuss."

Or, at least, little fuss. And not just in containers.

Though sun-loving succulents have shallow roots that dry out quickly, they can withstand long dry spells, even drought, by storing water in their fleshy leaves and stems. They're remarkably free of disease and pests and thrive in well-draining, otherwise poor, soil.

Among the most popular hardy succulents are sedums, commonly called stonecrops, and sempervivums, known as hens and chicks or simply "semps."

There are more than 800 sedums out there. Many, like the needle-shaped, golden yellow 'Angelina' and the aptly named 'Blue Spruce,' are prolific ground covers. Others, like the salmon-flowered 'Autumn Joy' and the newer, purple 'Black Jack,' bloom late in the season. They're tall, well suited for the back of a border.

"They're hardy performers, they're beautiful, they bloom their hearts out, are fairly easy to reproduce, and they spread easily through your garden," says Debra Lee Baldwin, author of Designing With Succulents, published last year by Timber Press.

The same could be said for "semps," of which there are about 4,000 kinds. Like sedums, they're also natural candidates for green roofs and rock gardens.

In fact, says rock-garden expert Gwen Moore Kelaidis, "Sempervivums are essential to the rock garden. You can stuff them anywhere. They will fill any spot . . . and they're good for 'knitting' the rocks, making them look like they're closer together than they are."

Kelaidis, author of Hardy Succulents: Tough Plants for Every Climate, published in March by Storey, has 30 border sedums in her small Denver garden and 200 sempervivums, many in containers.

And just as Hojnowski is smitten with her green roof, Kelaidis is enamored of her burgeoning "sempervivum lawn." She's filling a former grass patch 30 feet long and 3 feet wide with hens and chicks. Few tasks, for her, are more delightful.

Says Kelaidis: "You have to buy green ones and red ones, green ones with red tips and red ones with green tips, ones with little rosettes and ones with big rosettes, ones with fuzzy tips on leaves and ones that are velvet or have little hairs."

It's not as expensive as it sounds, for succulents are easily divided. Hens and chicks, especially so. Just pluck the chick from the hen and plant it or give it away.

Cheap (you might say cheep) trick, one that comes in handy when rationalizing one's horticultural spending habits.

"Compared to going out to dinner, plants are cheap," says Kelaidis. "So you make tuna casserole for dinner and buy yourself some more sedums."

Virginia A. Smith blogs at http://go.philly.com/gardening.