An Outdoor Playroom

One of the best features of this project is that you won't have to dig into your children's college fund to pay for it. A professional would charge about $2,000 for the custom-designed sandbox, bike path and arbor, but parents can buy the materials for only $550 and do the project themselves. This project is rated a 2 on a difficulty scale of 1 (easy) to 5 (difficult) and can be completed in two weekends.

Step One: Installing the Sandbox

Landscape contractor Efren Herrera of Summer Rain Landscaping installed the 7- by 7-foot semicircular sandbox with a cobblestone seating wall around the perimeter. Materials for the sandbox cost about $150, and once the kids outgrow it, you can easily turn it into a planting bed.

Clear the site of the play area. Define the semicircular shape of the sandbox using a piece of bender board, and mark the outline with landscapers' spray paint. Dig out the sandbox pit to about 1 foot deep.

To make a footing for the cobblestone seating wall, place a 1x6 bender board inside the curve about 6 inches in from the outer edge, and stake it in place. Shovel in about 7 inches of quick-setting concrete, and smooth the concrete with a trowel. Let the concrete set overnight, and remove the bender board.

Place the bender board on top of the footing, along the inner edge, and secure it with stakes. Attach a second bender board on the outside of the 6-inch-wide footing, and add spacers to maintain the gap and create a frame for the wall. Shovel in mortar, almost as high as the frame. Sink a row of cobblestones into the mortar, around the perimeter. Wipe any excess mortar off the stones, and let set overnight before removing the frame.

Step Two: Building the Bike Path

Herrera used gold-colored decomposed granite for the 17-foot-long, 4-foot-wide path, and the path materials cost about $80.

Shape the path with a few gentle curves, using 1x4 bender boards and marking the outline with landscapers' spray paint. Dig out the path about 4 inches deep, and frame it by staking the bender boards in place. Lay landscape fabric along the entire length, cut to shape.

Fill in around the paw prints with a half of a cubic yard of decomposed gravel (or more for a longer path). Level it out to just below the top of the frame, and pack it down with a hand tamper. Brush any excess granite off the paw prints. Figure D shows the completed bike path.

Step Three: Completing the Playspace

Herrera built a miniature arbor at the end of the path for about $75. It's easy to remove after the kids outgrow it.

Dig out a post hole on both sides at one end of the bike path, to about 18 inches deep. Set 8-foot-long 4x4 redwood posts into the holes. Fill the holes with water, pour in quick-setting concrete, and mix it in place. Check that the posts are plumb, and let set overnight.

Finally, to make the raised planter more kid-friendly, build shelves along the front to serve as a work space for special projects or as steps for the kids to climb up (figure G). The planter is a great place for kids to learn about planting and growing herbs, vegetables and flowers.

Planting: An Outdoor Playroom

Lu chose plants with a rainbow of colors and interesting patterns and textures, making sure that all plants are nontoxic. She framed the sandbox with flowering shrubs in vibrant shades of red, yellow, and purple and a fruit tree as a dramatic focal point. She filled in the raised planter with an assortment of blooms and fragrant herbs and decorated the bike path and arbor with more color to carry on the cheery look. The child-friendly plants include:

• Cigar plant (Cuphea ignea), Zones 10-11
• Autumn sage (Salvia greggii), Zones 7-9
• Strawberry tree (Arbutus unedo), Zones 7-9