Many gardeners use fluorescent lights to start young vegetable and flower plants during the spring or to grow certain houseplants all year long. And no, you do not need the special “grow” lights for this.

Traditionally we have used the basic shop light suspended a few inches above the tops of the plants with the common T-12 lamps. But there are newer lamps that may be a better choice for indoor gardens. These are known as T-8 and T-5 lamps.

The number after the “T” refers to the diameter of the lamp in eighths of an inch. Therefore, a T-12 lamp is 12/8 or 1.5 inches in diameter, the A T-8 is 8/8 or 1 inch in diameter and a T-5 is 5/8 of an inch in diameter.

So does a smaller diameter mean less light? Not at all. The T-5 is the brightest of the three. A T-12 lamp puts out 1,500 to 1,700 lumens for a 48-inch lamp. This lamp has a life of between 10,000 and 20,000 hours. The T-8 lamp produces 3,400 lumens and has a 40,000-hour life expectancy. The T-5 is rated at 5,000 lumens but lasts only 30,000 hours.

Lamp life is a weak selling point. A lamp turned on for 12 hours every day would take almost seven years to reach the 30,000-hour mark.

Another advantage for these newer lamps is they use less electricity per lumen. Our traditional 48-inch T-12 is rated at 40 watts, the T-8 at 32 watts and the T-5 at 54 watts. So are there drawbacks? Of course there are.

First, you cannot use your existing T-12 fixtures but must use fixtures made for the type of lamp you buy. The T-5 fixture that holds four lamps would cost about $200 (About $60 of this cost is the four T-5 lamps included). A three-bulb T-8 fixture with the three bulbs costs about the same ($200) but would not produce as much light. But the T-8 lamps use less electricity per lamp and last longer.

The question becomes, is it worth it? If you have a single fixture and are satisfied with your results, then probably not. If you have a more extensive setup and/or want your plants to be stockier, then these might be of value.