Signs at garden centers proclaim the news: "Tree Tops Are Here!" But don't be tempted to just buy a bunch of spruce branches and plop them in a container tied with a big red bow.

By using a few interchangeable elements, you can give your pots punch that will last from Thanksgiving to March.

"In the wintertime, I'm not just designing for Christmas or New Year's, I'm designing for the winter season," said designer Brian Winter of W&S Design in Minneapolis.

With minimal effort and a little creativity, your front steps can go from boring to best-dressed.

Raid your garden

For a look that will last through the winter season, "think neutrals and natural," said Larry Pfarr, owner of Leap Retail Consulting. The ingredients can even come from your own back yard.

Duane Otto, a landscape designer at the Minnesota Landscape Arboretum, gathers elements from the arboretum grounds: the golden heads of Annabelle hydrangeas, the soft brown of dried astilbe flowers, the showy seedheads of Joe Pye weed, fistfuls of ornamental grasses such as miscanthus.

"Use what you have," said Otto. "It's your creation. It doesn't have to have a particular style."

Getting started

Pfarr recommends starting with containers that are in scale with your front steps. (He often uses three for visual appeal.)

You can use the same pots you used in summer, and if your containers are unbreakable, you can even use the leftover soil to anchor your display. However, freezing and thawing can crack a ceramic pot filled with soil.

That's why experienced designers take precautions. Otto removes the soil and replaces it with sand. Pfarr adds Styrofoam peanuts to the bottom of a ceramic pot and strips of foam along the walls, then adds dirt.

Going for the green

Rely on evergreens for the backbone of your design.

Pfarr starts with a mix of evergreens, mixing tree tops with two or three other kinds of evergreens, such as white pines or junipers, for texture. (You also can buy a pot of mixed greens at a garden center and dress them up.)

"Then, you can do whatever," said Pfarr, "from glitzy to a more natural look."

Design details

When you add other elements to your base of evergreens, "think in threes" advised Pfarr, "and keep them grouped together." Your design should radiate out from a central point, he said. He also suggests that you add elements that trail over the edge of your container.

Jennifer Guion, owner of the Luna Vinca floral shop in Minneapolis, recommends limiting the type of elements you add.

"Use five elements at the most," she said. "Things have a bigger impact if they have some repetition to them."

Remember to add some height to your arrangement, whether through natural or manmade items. A good rule of thumb, said Otto, is to use something that's about twice as tall as the container.

When he created seasonal containers for the arboretum, Otto added a spike of cherry-red Cardinal Dogwood branches (a University of Minnesota introduction). He also surrounded the base of the black-glazed pots with drooping white pine limbs and small branches of oak leaves, which he rescued from a downed tree that was headed for the chipper. "The leaves of oak trees will stay on most of the winter," he said.

Holiday-specific focus

Top off your arrangement with a focal point. If you want your container to look festive from Thanksgiving through the new year, make sure your focal point is one that can easily be changed.

For example, Otto nestled bright orange and white gourds into a container of evergreens and oak leaves for a Thanksgiving look. For the holidays, he'll remove the leaves, wind red ribbon through the branches and add berries and glittered pine cones. Once the holidays are over, he'll remove the red ribbon and glittery additions.

(If your arrangement is too frozen to work with, Pfarr suggests pouring a pail of boiling water into the container, waiting a few hours, then adding new elements.)

For his focal points, Pfarr progresses from a grapevine ball surrounded by pine cones, to oversized Christmas, to a faux bird's nest accented with red dogwood twigs and artificial berries.

No matter how showy or restrained your outdoor arrangement ends up, Winter encourages you to give dressing up traditional spruce tops a try. "You're making your home welcoming and it's a nice way to do it," he said.

Gail Brown Hudson is a Minneapolis freelance writer, working on a master's degree in horticulture at the University of Minnesota.