Thryallis, Rain of Gold, Spray of Gold. Galphimia glauca. ( / April 10, 2012)

Tropicals will be hot this gardening season.

Forgive the pun, but growers and garden centers are responding to a demand from homeowners for the luxurious foliage and lipstick colors of plants more suited to the South.

And they are offering much more than the bread-and-butter varieties of hibiscus and mandevilla we are used to seeing in greenhouses.

"People want color," said Stephanie Thompson Fleming, owner of Behnke's Nursery in Beltsville. "The economy is terrible, and they want to make the place where they live look great."

"Tropicals are going to soar this year," said Lynne Whalen of Garden Media Group, which represents garden industry clients and tracks trends. "People want immediate color and something that is dramatic for their patio or their apartment balcony. They want 'interest,' and tropicals can deliver it all."

Maryland had a mighty mild winter, but it will never be mistaken for Miami. So plants that bloom year-round in the South must be considered annuals here, despite the fact that the average temperature in our plant hardiness zone has been inching up over the years. The new Plant Hardiness Zone Map, produced by the U.S. Department of Agriculture this year, elevates parts of Maryland to Zone 8, from Zone 7a or 7b.

During winter, "if you have a sunroom, you can bring them in," said Kerry Kelley, annuals buyer for Homestead Gardens in Davidsonville. "Or you can put them in the garage or the basement, and allow them to go dormant.

"But the advantage to these plants is they like the heat and humidity of Maryland summers, they bloom until frost and the majority don't need deadheading. They are pretty easy to care for."

And hummingbirds and butterflies are attracted to the vibrant colors of tropicals.

"The pool people have always bought tropicals," said Carrie Engel of Valley View Farms in Cockeysville. "But these plants are moving beyond that now, and they are a big part of the outdoor-living mentality."

She said homeowners are doing their research and are more educated about the variety tropicals offer and their ease of care. They want more than a simple potted palm or a banana plant, even asking for citrus trees such as Meyer lemon or Key lime.

"I think we kid ourselves a little bit," she said. Despite the best efforts of growers, these plants are never going to like 40-degree winters, let alone 20-degree winters. "But people seem willing to accept them as temporary plants."

Tropicals are most often planted in pots, making it easier to relocate them. But in the ground, they will grow quickly and offer dramatic color and foliage on a trellis, over an arbor or a fence.

They are more expensive than common annuals — $25 for a three-gallon pot — and the price may cause homeowners to hesitate. But Kelley says you get a lot of bang for those bucks. Homeowners just need to take the time to see the variety available.

"Bougainvillea and hibiscus are the ones people think of first, but bougainvillea ships badly and can look a little rough. And hibiscus takes a lot of water and fertilizer."

She recommends Jatropha, with red, coral or pink flower clusters on nice glossy green foliage and a compact growing habit — perfect for a large container. Or Golden Thryallis, also known as Gold Shower, with small yellow flowers that run to the top of the stem. "A lady came in to reserve hers to make sure she gets one. They are just so easy," Kelley said.

Sky-blue flowers make Plumbago popular, with its varied growth habit. "It trails and weeps and stands up-right. But it is the color people love."

Ruellia, or Mexican petunia, has blue trumpet-shaped flowers that only last a day, but it blooms furiously all summer, and some gardeners have told Kelley that it has successfully overwintered in Maryland. Every neighborhood — indeed, every yard — can have many micro-climates that might allow this to happen.

If foliage is what you crave, try Acalypha, also called Copper Leaf. But it can have shades of anything from green and yellow to orange and burgundy, with different patterns and leaf shapes.