I've spent too much of my gardening years guessing. Is this spot in the garden too sunny to qualify as a home for a part-sun plant? Is that location too shady for a part-shade specimen?

In this climate, when a plant label broadly stipulates "sun to part shade," it's better to place the plant in conditions on the shady end. But for amateur gardeners, how is one to know how much shade is too much?

The path of the sun, the effects of shade trees and shadows produced by the residence, outbuildings, walls and fences all contribute to a varied amount of available sunlight. There's a new gadget on the market that takes the guesswork out of the equation.

SunCalc

The SunCalc reads the intensity of the sun's rays.

The SunCalc is designed to calculate sunlight conditions during the gardening season. The device, which measures solar radiation, is calibrated to match the universal cultivation designations of full sun, partial sun, partial shade or full shade.

The tool looks like a probe, but the business end is its round face, which measures the sun's rays in the same way a plant's leaves receive the sun's energy. All you have to do is place the unit so that its face is parallel to the ground, activate its battery, leave it in place for 12 hours and then you get your reading.

According to the manufacturer, the invention was tested against the official radiometer at a global warming solar monitoring station operated by the University of Maine and the federal government. The SunCalc produced "virtually identical" readings.

The SunCalc is available for about $30 at several online sites, including burpee.com, gardeners.com, gardenersedge.com and whateverworks.com. For more information, see www.thesuncalc.com.

Special issues of Fine Gardening magazine and Southern Living are devoted to container gardening ideas.

When it's too hot to work in the garden, I like to daydream about what might be by reading garden publications. Two special-issue magazines on newsstands now are about container gardening.

Taunton Press, publisher of Fine Gardening magazine, includes tips and examples from 10 garden professionals spanning the nation's horticultural zones. It's interesting to see what gardeners are doing in other regions with the same plants we see for sale in North Texas.

The mixed container still reigns, whether the finished planter is a dish garden of succulents or a giant urn filled to overflowing with pink and red caladiums, pink-blooming mandevilla and gray-leaved licorice plant.

The issue ($7.99) is filled with pretty photographs and inspiring examples, including container gardens that thrive on low water, lush window boxes and water gardens in a pot. The plants are identified, and how-to tips are generous.

Southern Living also contributes to the container craze with its own Container Gardening special issue ($9.99). Inside are more plant combinations, ideas to summerize a front porch with flowers and cooling greenery and instructions for keeping containers full and flourishing.