Yardsmart: Your own octopus' garden

"I'd like to be under the sea / in an octopus' garden in the shade." These lines of the Beatles' famous song ran through my head as I marveled at a unique "undersea" garden. Situated not far from the San Diego coast, and designed by the folks at the San Diego Botanical Garden, this garden reflects a beautiful undersea landscape using nothing more than stones and plants. Best of all, it is incredibly drought-resistant.

For anyone who loves both the sea and the garden, this is the perfect blending of the two. Take a look at encyclopedias or documentaries to get an idea of the beauty of coral reef. More importantly, you'll see forms and colors that mimic many terrestrial plants. These resemblances are the basis for fun and educational garden designs for children and adults alike.

The backbone of an undersea garden is the lava rock, which contains lots of nooks and crannies. This resembles how coral grows under water, offering protected recessed homes for many forms of sea life. Virtually any other kind of local rock can be used, provided it features these irregular pockets for planting.

Even if it's one or a dozen lava rocks, don't just set them on the ground. Get a more realistic look by planting them naturally into slightly raised mounds. This is also ideal for enhanced drainage, particularly if you add a lot of sharp sand to the fill material. Sharp sand is sold in bags for plaster at the home-improvement store, or you can buy in bulk for larger projects from a masonry-supply store.

This garden is doable in a multitude of climate zones where you can substitute with many other kinds of plants. The key is to zero in on shapes that mimic those of marine organisms. Be aware of colors and textures, too, which offer plenty of variety.

Alpine succulents are ideal for northern gardens because these are remarkably resistant to cold. Many Sedum species and hybrids are the best sources of color, from bright yellow to dark wine red. The small rosettes of Sempervivums are the best choice for symmetrical forms that resemble sea anemones. They are perfect for filling niches in the stones or small fissures for an instant, lived-in look. Smaller ornamental grasses such as blue fescue is perfectly sized and colored to offer textural contrast to your hardy succulents. Taller grasses with wider leaves make good "sea grass" that come alive with the slightest breeze, lending a fluid animation to the overall composition.