Gravel is easy on the eye and on the pocketbook

Gravel is an overlooked material for surfaces in the garden. Used on paths and patios, gravel is an economical and attractive alternative to concrete, flagstone and brick.

Long used in European and Asian gardens, it is adaptable to many garden styles.

The key to its successful use is in the details of careful selection, edging and layout.

The most available gravel, commonly used on driveways, is called 5/8" minus crushed rock, broken down from larger rocks.

The material is screened so that the finished product has a range of sizes from 5/8 inches down to sand-size pieces.

The smaller pieces are called fines, and they settle into the spaces between the larger pieces so that the gravel packs down well to create a firm surface. You can hurry the process by watering with a hose, or just let the rain wash it in.

This gravel makes a good surface for paths and patios. Color can vary slightly from batch to batch and between suppliers, in shades of gray with blue or brown tones.

Visit places that sell gravel to check out what's available (look in the phone book under "Sand and Gravel").

Specialty gravel

This type of gravel brings color to the garden. Terrazzo chips are made from crushed marble. Their primary use is for making terrazzo floors, where they are put into a cement-like mix, spread onto the floor and, after drying, ground smooth.

The chips come in a range of colors, including tan, cream, blue, green and red. The chips come in three sizes and are sold by the bag at Terrazzo & Stone Supply in Bellevue.

Another source for colored gravel is Manufacturer's Minerals in Renton. They carry a wide range of gravel made from many different types of rock.

Create your own custom mix for a distinctive look. Specialty gravel is more expensive than crushed rock, so consider using it as a top dressing over less expensive 5/8" minus.

Pea gravel should be used with caution in gardens. It looks just like its name, round pea-sized stones. Pea gravel can roll underfoot. A client asked for pea gravel, saying he wanted to walk barefoot in the garden. After placing it on a patio and paths, the client found it so uncomfortable to walk on (he said it hurt his back because of the shifting) that he replaced it with lawn.

If you do want to use pea gravel, place it just an inch deep as a topping over crushed rock to provide a firm foundation.

Gravel amounts

To calculate how much material you need, remember that 1 cubic yard of gravel will cover 300 square feet 1 inch deep. Add the number of square feet you want to cover; divide by 300; and multiply by your desired depth, in inches, to get the number of cubic yards to order.

Gravel surfaces should be 4 inches deep to give stability and keep weeds from growing up from the soil below. If you want to decrease the depth, consider using a heavy-duty landscape-fabric weed barrier. Don't use black plastic if you want the area to drain.

Weed seeds can blow in and germinate in gravel. Foot traffic keeps them down, but in less walked-on areas, you can use a product containing vinegar, such as Burnout. Unlike some other herbicides, vinegar will not affect wildlife and groundwater.

Dressing up gravel

Add style to your gravel surfaces with edging, and separate them from adjacent lawns or planting beds. Brick or cobblestone is easy to lay in straight or curved lines. Wood makes a serviceable edge but will need replacing occasionally. For an almost invisible edge, use steel lawn edging or plastic edge restraints made to contain pavers.

Gravel paths can be dressed up with stepping stones set into the paths or with bands of stone or brick laid across them. Gravel makes a good surface for stair treads contained by timber or stone risers.

Because gravel makes a good base for stone, you can start out using gravel for your paths and terraces and lay stone on top when the budget allows.

You may grow accustomed to gravel's crunch underfoot, the clean look and the easy care enough to stick with the gravel touch in your garden.

Phil Wood has a degree in landscape architecture and designs and builds gardens. Send questions to thegardendesigner@seattletimes.com or call 206-464-8533.