Siblings Erin and Christopher Rogoff share their backyard with chipmunks, squirrels, bats and rabbits. They help their parents fill bird feeders, hang bat boxes and plant fruits and vegetables to attract wildlife.

"The squirrels chase the birds, and Erin and me chase the squirrels," said 7-year-old Christopher, who loves playing out in his yard in Ocean Township, N.J. His parents, Marc and Bernadette Rogoff, wanted to create a fun backyard that would encourage their kids to appreciate the outdoors, entertain themselves and have unstructured down time.

"It's really important to have a connection with the outside," Bernadette Rogoff said. "Kids really need time to figure out who they are. Goofing around outside gives them time to do that."

Landscapers and designers say that creating fun outdoor spaces is simple and inexpensive.

Nancy Striniste, owner of the company EarlySpace in Arlington, Va., recommends designating spots for exploration, imaginative play and observing animals. Also be sure to include grassy areas for games, running and play sets, she said.

Plants, water and stepping stones can all play a role in creating a kid-friendly yard.

Striniste often uses stone pavers or border plants to make meandering paths for children. She plants herbs between the stones because their distinctive scents will make the adventure more fun and create long-lasting memories.

"The scent of lilacs just takes me back to my childhood," she said.

Fountains or small ponds also are fun because children love to play in water. Striniste's son spent hours last summer using a net to catch and release the goldfish that live in the family's backyard pond.

"We bought them for 25 cents at the pet store," she said. "They got big and had babies. It's very exciting."

A water element also will bring animals into the yard, Striniste said. Families interested in attracting animals should consult the National Wildlife Federation's guidelines for creating a backyard habitat. The federation awards certificates to households that meet the agency's requirements for providing food, water and shelter for animals. Information is available on the federation's Web site, NWF.org.

Using plants to good effect

Another idea is to use plants to create cozy places that encourage make-believe, Striniste said. The space under an evergreen, for example, can be an inviting place for little ones. So can a playhouse made from flowers and vines.

It's possible to make a living playhouse by planting sunflowers in a large square and training morning glory vines to grow between them, she said. Planting vines on a trellis or chain link fence also can create a natural play area.

"It is very important to give kids a sense of place and space," said Sam Scarborough, author of "Cool Spaces for Kids" (Octopus Publishing Group, $19.99). "They love being contained in an area that they feel belongs to them. Children like to have boundaries - it makes them feel safe."

Scarborough's book offers ideas on how to create tents and tepees from bamboo poles, fabric and hula hoops.

"Pitching a tent in the garden and adding a few comfy cushions and blankets is a very easy way of getting kids to go outside and play," she wrote in an e-mail from her home in Cape Town, South Africa.

Planting a garden is another way to encourage children to spend time outside.

"Watching a plant grow is a lovely experience for a child," Scarborough said. "It is even more fun if you can enjoy the crop as a meal."

Marc Rogoff's children love eating the produce from their garden. The kids would rather "nosh on blueberries from the garden" than a bowl of candy, said Rogoff, an environmental educator.

Twelve-year-old Erin agreed.

"I like them better when they're planted in nature," she said. "They taste more sugary."