Adding An Artistic Retaining Wall

Take a steep hillside that some people might consider a negative feature and play it up: with a little hard work and creativity you can turn it into a beautiful focal point in your yard.

The landscape designer for this project, Diane Bloom, has an idea that will solve the problem: she wants to build a series of retaining walls of stone for a natural rustic look. They'll help hold back the hillside and catch water runoff, but they'll also create defined levels to the hillside. Building pockets, platforms and nooks into the walls will provide places to decorate later on with garden art or pottery. The walls create an artistic, personalized look in the garden.

This project takes about three weekends to complete, and you won't believe how much money you can save by doing it yourself. A professional would charge $3500 or more for this project, not including plants. That's because you pay for materials, labor and a design fee. Because this is such an artistic project, it requires a well thought-out design. If you do this project yourself, expect to spend only about $1400, not including the plants.

This project requires you to work on a slope and with stone, so there is some effort involved. Bloom rates it a 4 on a difficulty scale of 1 to 5, with 1 being the easiest. She says that as long as you work slowly and carefully, and maybe get a few friends to help, this definitely is a project you can do on your own.

Figure A

Step One: Building the Walls

Begin by removing the vegetation growing on the hillside. Use flags to mark out the curving shape of the walls.

Figure B

Bloom uses a couple of different types of local stone — rounded, moss-covered field stones that have a pretty, mottled look (figure A) and porous wall stones (figure B). The wall stones have a slightly square shape and they're laced with holes, which adds visual interest. Both of these stones are local to Northern California; Bloom suggests that you use stones found in your area.

Figure C

Drystacked walls may not seem strong enough to hold back a hillside, but in fact they are very strong--some can even withstand an earthquake. The secret is to angle each rock into the slope slightly so that there's a good fit (figure C).

Tip: Take some time to look at your stones before you place them. Turn them over to find their best side. Look at their colors, shapes and sizes — notice if they have moss or other distinctive features. Pull out the ones you like best and set them in the most visible spots on the wall. Also, try to vary the look of the stones from one to the next for a more natural, rugged look.

Make safety your first concern. Be careful that you don't hurt your back — here are a couple things to keep in mind:

1. The closer you carry the weight of the rock to your body, the less chance you have of injury.
2. When you pick up a rock, lift it using your stomach muscles and hold it directly in front of you — don't twist around. You're much less likely to hurt yourself.

If you work in small sections then stand back and take a look at your work, it's easy to make changes before you move on.

The Landscape Smart crew also builds two more walls, with one set pretty close to the top. This wall will prevent water runoff from the street from flowing down the hill. Since it's located near several trees, they're careful to check the spread of the tree roots first. Bloom says you should do the same so that you disturb the roots as little as possible.

Figure D

For the last course of each wall, Bloom chooses stones with a flatter surface (figure D) so that the top of the wall looks more finished and isn't too wavy.

Step Two: Building the Platforms

Bloom creates three different platforms that are built out from the walls. Using three goes back to Greek principles of design and balance: groupings in odd numbers look more harmonious than groups of even numbers. She lays them out so that they have the spatial relationship of a triangle — this is to draw the eye to different parts of the walls.

Figure E

Bloom suggests that you make each platform different to emphasize the unique setting. She builds them out of a variety of fieldstones and flagstones in a very free-form manner (figure E). These platforms are fairly small and simple, but you can make them as big and ornate as you'd like. It's really a matter of taste mixed with a lot of trial and error — keep changing things until you get a look that you're happy with.

Planting Plan

Because this is a rather shady hillside, Bloom wants to use plants that will brighten it up. Besides re-using some of the plants that were removed at the beginning, she also chooses plants with lots of colorful blooms, or with foliage color and variegation. She varies the textures, incorporating some plants to cascade over the wall and give it a softer look, then adds grasses for a natural touch.

• Loropetalum chinense 'Plum Delight', Zones 8-9
• Licorice plant (Helichrysum petiolare) 'Limelight', Zones 10-11
• Jacob's ladder (Polemonium caeruleum), Zones 4-8

Step Three: Adding the Accessories

This is where you can put your mark on the garden and have it reflect your personal taste. In this case, our homeowner has collected a lot of objects with rustic, earthy charm. She has some small statues, some beautiful pieces of pottery and containers for plants. Place your favorite decorative objects on the platforms and between the plantings. Stand back and enjoy the hillside's new look.