Obelisks make a good point. They're an ancient garden ornament with plenty of modern style.

Obelisks give a garden a lift; they're monumental exclamation points that capture your eye and attention and help organize a space. Although the world's most famous obelisks -- Cleopatra's needles and the Washington Monument, among them -- are not exactly on the scale of garden ornaments, the dramatic form adapts very gracefully to gardens of every size.

Technically, an obelisk is simply a pointed stone pillar, but this basic definition has been broadly interpreted. Garden obelisks can be constructed of almost any material. Unlike a garden tepee for beans or peas, which is usually put together with just three tall stakes held together at the top, an obelisk is a sturdier construction, with a strong architectural presence in the garden. They are the perfect finishing touch.

A pair of obelisks at a garden gate have the stately bearing of sentries, but you don't need two: a single tall obelisk, standing proudly in a flower bed or at the bottom of a path, strikes a resounding and unifying note in a garden. Obelisks at the outer corners of a patio provide a subtle sense of enclosure, and they need not be tall to have this effect: by their very presence and uniformity, they lend a certain momentum, like chess pieces on a board, to even a simple setting.

Garden obelisks were perhaps at the height of their popularity in the 17th century, when Andre Le Notre, the great landscape architect of the palace of Versailles, set a pair of them at the gates to the French king's extravagant country estate. Within the gates, topiary obelisks held strategic echoing positions in the artful parterres. In the 17th and 18th centuries, trellis-work obelisks were used extensively in clipped and controlled Dutch gardens. Garden historians describe obelisks as "practically ubiquitous" in 18th-century English and Irish gardens, where stone obelisks framed the views. They were often engraved with commemorative inscriptions.

From European gardens, obelisks moved to America, where they took up residence especially in cemeteries. One theory about their popularity is that obelisks had a much smaller footprint and were less expensive than more magnificent monuments. Another is that obelisks evoked the great civilizations of classical antiquity to which the young nation was very eager to compare itself. They also had space for engraving on four sides, and were thus sensible choices for family plots.

In a graveyard, obelisks appear solemn and perhaps a little mournful; in a garden, they are certainly dignified, but not always quite so serious. In a tiny backyard in Virginia, a designer erected a rustic fieldstone obelisk at the back of his garden and topped it with a shimmering golden ball, like something out of a fairytale. Another gardener set tradition aside and topped her 10-foot obelisk with a charming birdhouse. Topiary obelisks of clipped boxwood, yews or other naturally slender evergreens, grown in ranks or as solitary punctuation points in a garden design, are living obelisks that need little attention. They become more and more commanding as they grow to their full height.

Wrought iron or wood obelisks are often put to work as three-dimensional trellises for clematis, annual vines, beans or tomatoes. They're great for clambering roses and evergreen honeysuckles because lanky growth can be confined within their tidy framework while the blooms shine through the structure. Small obelisks, designed to fit in big flowerpots, let you bring vining plants such as mandevillas up onto a porch, where you can appreciate their flowers up close.

Even if you're not very handy with tools, making your own obelisk is an easy project, well worth a few weekend hours. My husband and I downloaded plans from the Internet -- many styles and designs with pointed or square tops are available for free -- and made two obelisks last summer, a small one for a cucumber vine in a big terra-cotta pot, and an 8-foot-tall obelisk for a place of prominence in the middle of the garden. Once we had our materials together, it took us most of an afternoon to complete the job, but we took plenty of breaks to appreciate our progress. Both obelisks were an instant success, standing tall in the summer garden.

(For editorial questions, please contact Clint Hooker at chooker@amuniversal.com or the Universal Uclick Editorial Department at -uueditorial@amuniversal.com)

Many people work hard to make their gardens attractive to birds by setting up bird feeders, by growing plants that provide food and shelter for birds, and by keeping fresh water available year-round. But one of the most exciting ways to experience birds in your garden is to actually see them nesting in the low branches of an apple tree, in the azalea bushes, deep in a wisteria, in a holly or way up in a venerable oak. There's nothing quite like watching birds build a nest and raise their young right in your garden.

"It's a lot of fun. Finding a nest is like finding a treasure," says Robyn Bailey, who works with the NestWatch program at the Cornell Lab of Ornithology in Ithaca, N.Y. When people find a nest, they often think they shouldn't look too closely, but it's perfectly all right to watch.

"There's nothing like getting a glimpse into the intimate aspects of a bird's life cycle," Bailey says. She started her career as an official nest searcher, collecting information about nests for Cornell researchers, and now works closely with NestWatch, which encourages everyone to become an amateur bird biologist, tracking birds as they build their nests and raise their young.

Birds scouting for a place to build a nest are looking for more than a sturdy limb. They're hunting for habitat. A safe spot for a nest is part of that, but they also need water and food, in other words, plenty of bugs. Insects (and spiders) are full of protein, and they are the primary diet of most nestlings.

A garden with a bit of leaf litter under the shrubs looks very appealing to wrens and brown thrashers; they both turn over leaves constantly, snapping up bugs for themselves and their chicks. Birds also look for insects in the craggy bark of trees, on rose bushes, in the vegetable garden, under in the eaves, in every nook and cranny. Some birds (kingbirds, swallows, bluebirds and others) snatch flying insects out of the air. "Something like 4,000 insects are required for a chickadee to raise a clutch," Bailey says.

Most people find their first nest accidentally, she says. You might be trimming the shrubs and discover a cardinal sitting on her eggs, or you'll see a mockingbird coming and going from the boxwoods and hear the eager nestlings wake up with a peep every time she disappears down into the greenery. Some birds build their nests in plain view, in the tangled vines on a rose arbor or in a hanging basket on the porch. Carolina wrens, in particular, are not shy about nesting in potted plants, window boxes "or any little scrap of habitat," Bailey says.

Birdhouses -- the professionals call them nesting boxes -- enable you a to attract cavity-nesting birds, such as wrens, bluebirds, titmice, chickadees and woodpeckers, to a spot you know you won't miss. They're handsome architectural features in their own right, in classic or modern styles. Nesting boxes should be sturdy and well-ventilated; they do not need outside perches.

Once you find a nest in your own garden or in your neighborhood, you'll pick up on clues and start to see more -- you may discover a nest while you're walking the dog, or spot a mockingbird's nest in the bushes at the grocery-store parking lot. "It gets easier every time you find one," Bailey says.

Nests are all different, you'll discover. Some birds are tidy housekeepers, and others are scavengers, cobbling together their nests with unexpected assortments of local materials. Robins build rustic nests of grass and twigs, held together with mud. A blue jay's nest might incorporate scraps of plastic plant labels or twist-ties from the garden. A hummingbird nest, if you're lucky enough to spot one, is made with moss and small bits of bark and leaves, all held together with spider silk and camouflaged with lichen.

"They're all beautiful," Bailey says. "You have to respect the engineering that goes into a nest."

When you find a nest or discover birds building one, don't interfere with them. By the time they lay their eggs, they're pretty well committed to the nest they have built, Bailey says, and you can safely check on the nest every few days. It's OK to take pictures of the eggs or nestlings, but don't use the flash feature on your camera, and don't become a nuisance, she says. Don't handle the eggs. And go to the NestWatch web site to report on what you have found: it's a chance to contribute to important research, "measuring nature's success" in terms of nests, eggs and fledglings, NestWatch says. The science is important, but the rewards are measured in other ways, too.

"To me, watching nests is the most rewarding aspect of bird-watching as a hobby," Bailey says. She especially loves "that moment when the chicks are sitting on the edge of the nest getting ready to take their first flight." At that moment, you're flying, too.

SIDEBAR

NOTES ON NESTS

For more nest-watching ideas and resources check the Cornell Lab of Ornithology's NestWatch website (nestwatch.org), which includes information about birds and their nests and nesting habits, plans for nesting boxes and platforms, and suggestions on how and where to place them. YardMap (yardmap.org), also sponsored by the Cornell lab, encourages gardeners to map their property, showing backyard bird habitat features.

Here are some ideas to encourage birds to make their homes in your garden from Robyn Bailey, program assistant for both NestWatch and YardMap:

-- Provide nesting boxes.

-- Make nesting material available. You could fill a small basket with bits of wool or fabric scraps, feathers from an old pillow, shredded paper, cotton balls and short pieces of string. Leave it in an open place on the porch, or stuff it into a wire basket and hang it from a branch.

-- Do not touch birds' eggs. If a chick falls out of a nest before it is even able to stand on its own two feet, put it back quickly and gently, then move away from the nest.

-- Do not use insecticides and herbicides during nesting season. Most songbirds feed their nestlings insects.

-- When birds are nesting and nestlings are starting to fledge, "keep your cats inside," Bailey says. Young birds "need two or three days to figure out where they are and how to fly."

(For editorial questions, please contact Clint Hooker at chooker@amuniversal.com or the Universal Uclick Editorial Department at -uueditorial@amuniversal.com)

The gardening season never ends when you have a greenhouse: There's always something growing on.

Greenhouses give cold-climate gardeners the luxury of keeping their fingers in the dirt through the winter, and warm-climate gardeners a chance to experiment with truly tropical plants year-round. In any climate, a greenhouse is the perfect place to get ahead of the calendar and start seeds and tend to transplants. In a greenhouse, in the dead of winter, lemon blossoms perfume the air, basil and other tender herbs flourish, seedlings push happily up into the light and warmth. Not surprisingly, gardeners thrive in a greenhouse environment, too.

"A lot of people just want to sit among their plants and do nothing, just enjoy it," says Shelley Newman, vice president of Hartley Botanic, which has been making greenhouses in England since 1938.

Plant collectors used to be the main customers for greenhouses, says Charley Yaw, owner of Charley's Greenhouse & Garden in Mount Vernon, Wash. Orchids, tender cacti and fancy flowers filled the shelves in these elaborate structures. Now, a large new generation of gardeners interested in starting seeds early and vegetable gardening in the offseason is making room in its backyards for hard-working greenhouses.

"There are a ton more greenhouses being sold today than 20 years ago," Yaw says. "And it doesn't take a real expensive or sophisticated greenhouse to grow vegetables."

Greenhouses can be just about any size, but the experts generally recommend a greenhouse with a footprint of about 8 by 10 feet. Yaw's formula for customers is easy: "Figure out what you want, then add 50 percent," he says. If two people will be working in the greenhouse together, a 10-by-12-foot space allows more elbow room, Yaw says, and more growing space, too. Newman recommends an even larger size for real enthusiasts; Hartley Botanic's most popular greenhouse size is 11 by 20 feet. "I'll tell you this," she says. "Everybody underbuys."

Building restrictions and setback limits may influence your decision, so it's a good idea to check on local zoning regulations before you get started. Temporary structures may not be regulated. Barbara Damrosch and Eliot Coleman, owners of Four Season Farm in Maine, rely on temporary 10-by-12-foot hoop-top greenhouses placed right on top of the soil to extend the seasons in their vegetable gardens.

Putting up a permanent greenhouse requires a bit of planning. You want it to look nice in your garden. You'll have to consider the layout of your property and the relationship of the greenhouse to the rest of the garden and your home. It should be on the south side of your house to take best advantage of the light, and away from screening evergreen trees.

A path through the middle should be paved solidly, to avoid muddy feet; gravel or pavers under the growing benches also help keep the greenhouse tidy. It's practical to have a patio or pad of pavers, bricks or stone outside the greenhouse door; this area can also be used as a staging area for plants making the transition from the greenhouse to the garden.

Hartley Botanic's greenhouses have glass panels, but not all greenhouses use glass. Plastic polycarbonate panels are popular, Yaw says, and the material is especially good insulation. Polycarbonate also diffuses the light, so plants do not get burned in bright sun.

Depending on where you live, an electric or gas heating system may be necessary, although passive heat will suffice on many days. Fans and automatic vents help prevent overheating.

Donna Clark, a retired garden designer in Greensboro, N.C., had a modest, hardworking greenhouse on the back of her two-car garage when she lived in Connecticut. When she and her husband sold their house and moved south, her dream of a Hartley Botanic greenhouse came true. Her Victorian-style greenhouse is just 11 by 10 feet, with a gravel floor. Shelves for plants line the sides, and a potting bench fits neatly against the back wall. "Some people want a fancy car," she says. "I wanted a fancy greenhouse."

Clark grows annual flowers from seed in her greenhouse, nurturing the tiny plants before transplanting them into the garden; she also starts seeds for her extensive vegetable garden. Last year, she grew cucumbers in the greenhouse, and harvested them long before cucumbers could have been produced in the garden outdoors. This winter, she is using her greenhouse as a studio experimenting with mosaics.

Greenhouses are not an impulse purchase. Inexpensive do-it-yourself models start at about $500 and run up to about $2,000. Larger greenhouses with more features are substantial structures and cost $5,000 or more. Hartley Botanic's fancy Victorian greenhouse is quite an investment, at $45,000 to $50,000.

The winter months are the perfect time to be considering a greenhouse. Some models are on sale, and if you get started now, you can have plans in place so that construction can proceed quickly, whenever the weather allows. You'll be out there with seed packets in hand, long before the gardening season begins for everybody else.

SOURCES

-- Charley's Greenhouse & Garden; www.charleysgreenhouse.com

-- Gardener's Supply Co.; www.gardeners.com

-- Hartley Botanic; www.hartley-botanic.com

-- Growers Supply; www.growerssupply.com

(For editorial questions, please contact Clint Hooker at chooker@amuniversal.com or the Universal Uclick Editorial Department at -uueditorial@amuniversal.com)