plants and rocks; the basics

If your idea of a good life means being surrounded by plants, chances are you love having a few rocks around too, even if only in a haphazard, barely intentional way. Perhaps small rock mementos from travels naturally seem to congregate indoors in bowls on shelves or outdoors in pots in the garden. Boulders, pebbles, crushed rock, gravel, we all have some form in our gardens, whether native rock (lucky you!) or imported, which apart from sheer usefulness and relative affordability also taps into an intuitive kind of garden sense, for rocks are the literal building blocks of soil. (And yes, there is an acronym for soil formation, CLORPT; Climate, Organisms, Relief (topography), Parent Material (rocks & sediment) and Time.) And when you bring a rock home or dig one up in your garden, there it will remain until you either move it again or someone else moves it after you’re gone. That paradoxical combination of permanence and transience continually inspires garden makers and artists like Andy Goldsworthy (see Walking Wall).

We’ve been relying on the ubiquity and indestructibility of rocks as a building material since forever. In gardens rocks are a malleable material, forming walls, walkways, modeling space, used as mulch and to create drainage in gardens where none existed, and building habitats for plants and creatures. But there’s a whole other level of wonder when plants grow among rocks, spreading and clinging and making it their home like undersea creatures colonizing a reef. Recreating such habitat is what consumes rock gardeners, and I saw some wonderful examples recently in Denver.

The North American Rock Garden Society has an invaluable archive of articles and an amazing seed list to begin or further your obsession with this kind of garden. (See also recently published “Rock Gardening; Reimagining a Classic Style” by Joseph Tychonievich.)

Growing high altitude alpine plants in Los Angeles’ zone 9-10, with their imperative needs for snow cover and/or winter dormancy, is not where we should direct our energies (and plant lust). Succulents, of course, are wonderful among rocks, and we can grow many small native iris and eriogonum, dianthus, erodium, flowering oreganos, sedges, nepeta — there’s lots of scope for experimenting.

Rocks are a classically integral component of dry gardens, and locally they seem to get the most sensitive and respectful treatment in desert gardens.

In the work of some artists, rockwork upstages plantings.

Next time you’re hiking in the Southern California foothills or Greece or the Sierras or the Rocky Mountains, see for yourself what plants and rocks are up to, because gardens can get really interesting when we understand how well they play together.