Decorating by the Process of Illumination

By Adrian Higgins
Thursday, December 18, 2008

At this time of year, the world divides into two types of folks. The first has a compelling need to string outdoor lights on bushes, trees, eaves, indeed whatever will take to illumination. The rest of us don't.

There is no smugness here. I admire a tastefully illuminated plant, but I've never felt the need to get up on a ladder to wrestle with a strand of wires and bulbs. There are other reasons: I don't like public displays, I enjoy the flora in its natural winter state, and, all right, I'd rather be by the fireplace reading a good book.

One year my daughter turned to me and asked, "Dad, how come we don't do outdoor decorations like everyone else?" Coming from an aggrieved 11-year-old, that was a like a stake through the heart, of course. Every year, the admonishment pushed me closer to joining the twinkly-light gang, but never quite close enough.

This year, I decided to put things right. I can now look out to my garden patio and see a 12-foot-high stewartia tree festooned with a medley of bluish light-emitting-diode lights and yellowish incandescent lights. It is not as elegant as I would have liked, it actually underscores the disappointing branch structure of this particular specimen, and it wouldn't hack it on the Mall or Las Vegas, Objectively, it could be judged for what it is, a novice's first effort, but as I told a friend, there's a lot of me in that tree.

I prefer to light deciduous trees rather than evergreens. I don't see the point of having a Christmas tree in my yard when I have one indoors. I would have preferred to string my young black gum tree, but it was too far from an electrical outlet. Long chains of extension cords are not only unsightly, they can overheat and cause fires. The stewartia is five feet from a socket equipped with a ground fault interrupter.

Don't wait too long to buy your lights, as I did. By this week, the stocks of classy strands of little white lights are low. There is a surfeit of "icicles" that you hang from your eaves, and there are a lot of really tacky illuminations stalking the procrastinators. At one place, there was a white plastic tree with built-in lights, and at another, a clear plastic tube in which lamps glowed in jarring colors. It conjured up an image of a squid, though I'm not sure why. The tackiest thing was a life-size mailbox, lit up and motorized. As the lid swung open, greeting cards peeped out. Maybe it'll go on sale after the holidays.

Before I started my project, I called a couple of experts on tree lighting to get some pointers. Rule No. 1: Make sure the lights you're buying are designed for outdoor use.

At Longwood Gardens in Kennett Square, Pa., arborists, gardeners and electricians use cherry pickers to install lights on 91 mature trees. They start in August to be finished by Thanksgiving. My project, by contrast, took four hours and an eight-foot stepladder.

Among the trees getting the treatment at Longwood are mighty specimens of copper beech and kousa dogwood that put my stewartia to shame. But the principles of lighting are the same, said Roger Davis, a senior gardener at Longwood. The strands are wrapped in a spiral fashion up the trunk and along enough of the main branches to give the proper effect. If you don't extend the strands to the tips of the branches, you have a jumble of lights within the tree's framework that "looks silly," he said.

For their large trees, the Longwood gardeners use strands that have lights every six inches; if they had used my strings' four-inch spacing, the effect would be too bright and overpowering. They have also been moving away from incandescent lights toward the LED types. They are more expensive (though I got mine 40 percent off this week for showing up so late in the season), and they emit a bluish-white light that is too glaring for their taste. Davis said manufacturers have come out with a warm white version that looks more traditional.

Davis and his colleagues now have 80 percent of their lights in LED, and the electricians calculate conservatively that electricity usage is down by 80 percent. Using LED lights not only saves money and reduces your carbon footprint, but it permits more strands to be linked safely. Manufacturers of incandescent lights say you should connect no more than three strands to each other. Longwood's conservative rule for LED lights is a maximum of 10 strands together, Davis said. A small ornamental tree might take 10 to 12 strands. If you wanted to tackle a larger tree, you would need to use additional extension cords on separate circuits.

The lights don't warm the tree out of its winter dormancy, Davis said, but they are not meant to be permanent. Light strands left on trees for more than one growing season can restrict growth and do serious harm to the plant.

On the Mall side of the National Museum of American History, Smithsonian horticulturist Brett McNish has wired an avenue of 16 crab apples using amber-colored LED lights. The hue catches the eye from across the Mall better than white while remaining neutral, he said.

He prefers to illuminate deciduous trees. "There are so many unique habits that really come alive when I wrap lights on them," he said. "My personal style: I don't want the thing to look like it's on fire."

Whoops. I may have gone overboard, but I'm pleased with the way my starter tree turned out. Let's hope my daughter agrees. She'll be visiting soon from Boston, where she's a graduate student. Hey, what can I say: I'm slow off the mark, but for 2008 I've seen the light.

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