Container gardening is growing smaller.

Suppliers are downsizing this season with easier-to-use trough planters, raised beds, pots or bags. It's an effective way to produce edibles or blooms in tight spaces.

One of the leaders in this less-is-better concept is EarthBox, a Scranton, Pa., manufacturer of self-watering plant containers. A half-size version designed for growing herbs and salad greens outdoors on deck railings, patios, rooftops and fire escapes, or indoors from kitchen windowsills, was introduced in January.

"It was a consumer-driven product," said Frank DiPaolo, EarthBox's general manager. "People told us they were interested in using self-watering technology for leafy greens and herbs and for growing them inside. For that purpose, the original EarthBox might have been too big."

Like the EarthBox original, the compact "Junior" has a water reservoir that wicks moisture to plant roots, reducing the need for daily watering while boosting yields. Junior measures just 23 by 7.25 by 9.5 inches, compared to the original's 29 by 14 by 11 inches.

An estimated 17 percent of gardeners -- or about 20 million households -- do their growing in containers, often in restricted spaces, said Bruce Butterfield, market research director for the National Gardening Association.

Many people don't have the need or the urge to grow eight or 10 herb plants, DiPaolo said. "Going downsized gives them a chance to grow just a couple of things they desire. Then they can free up their standard-size boxes for tomatoes and larger plants like that."

Containers come in all shapes and sizes and are particularly popular with urban gardeners. They are portable, easy to reach across, and absorb more of the sun's heat for faster plant growth than in-ground gardens do.

"They're also good season extenders," DiPaolo said. "I have mine sitting on the edge of the driveway. If I have tomatoes that are still bearing in late fall, I simply roll them into the garage overnight to protect them from frost, and then roll them back out again in the morning for some sun."

Tiered planters, window boxes, hanging baskets and grow bags also qualify as small space planters.

"Bags can easily be stored from season to season if you live in an urban area," said Maree Gaetani, a spokeswoman for Gardener's Supply Co., in Burlington, Vt. "We have raised beds [kits] now that you can set right on your patio."

Most common garden vegetables can be container-grown, although plant breeders have developed some new dwarf varieties that produce uncommonly high yields. Shallow-root edibles that perform well in pots include lettuces, peppers, onions, carrots, radishes and herbs.

"What really matters when you're growing vegetables in containers is making sure you fertilize," Gaetani said. "It also matters what kinds of soils you use so they aerate properly. Growing the right kinds of plants, giving them the right amount of water and finding locations that provide at least five hours of sun per day also are important."

Using the smaller, lighter containers makes it a great deal easier to move them there.