Waterwise gardening

All the rain last week (hooray for that) meant lots less time outdoors (since it was pouring) and in the garden (actually being back at work is the main reason). But shifting from home garden thinking to work garden ideas isn't too much of a contrast -- it all blends together in how I think about plants, gardening, ecology, environmentally-friendly approaches to gardening, and observing and learning more about nature.

I've been thinking quite a bit this week about sustainable gardening, and what waterwise gardening in our climate really means. Talking this week with my colleagues about updates for our xeriscape garden has me mulling over my approach to sustainable gardening.

I guess because my first interest in plants was those living in 'wild' landscapes that were native to the Texas Hill Country where I grew up, followed by a fascination with weedy species from a summer spent with my family in upstate NY (and visiting frequently in NYC) as a young teenager, and fortified by the tremendous plant diversity in California, where I studied plant ecology as a graduate student, I'm looking at our home landscape/garden with an ecologist's eye to plant behavior and needs.

The standard (US) horticultural recommendation of an inch of water a week sort of seems nuts to me. Is this a lawn thing? My pampered vegetable garden, well, yes, maybe, but our trees, shrubs and perennials (mostly native or tough) will happily get by on a lot less water. Uh, what about all the plants out there in the 'wild'? No one's watering them.

And we certainly DON'T need an irrigation system to successfully garden, even in times of drought.

I think being a waterwise gardener means choosing plants that can withstand dry spells, and flourish without lots of supplemental water (I wrote this in a post last September and this in October). Here in the SE (United States), we can grow lots of great plants that fit that description. Many of our native plants are prized in Europe as normal landscape plants, so this doesn't mean our palette is restricted to cacti and succulents.

Beth Chatto's gravel garden in East Anglia, England (20 inches of rain/yr)

She uses lots of Mediterranean natives in this garden.

Long hot summer dry spells (3-4 weeks) are not uncommon here in the Southeast, so native plants exposed to these conditions (those that don't live along streams,rivers, in floodplains, or in the mountains) have various adaptive strategies to cope, either through different types of tolerance mechanisms or avoidance (by being dormant). Clues to drought-tolerance come from native habitat (grasslands, prairies, dry woods, shallow soils, rocky slopes, etc.), plant habit (deep tap roots or fibrous storage roots), leaf color and texture (gray leaves are reflective, waxy or thick leaves are water-loss resistant).

What really gets me cranky is our American/Southern focus on lawns. In our home garden, we have perfectly nice areas of Zoysia lawn, established many years ago, and greatly diminished in size since we moved in. They never get a bit of supplemental water from us, nor any fertilization, aeration, de-thatching or anything else resembling 'lawn care.' The clippings are left to decompose and renourish the lawn. The lawn patches that are most exposed to sun and on shallower soils have suffered during the drought, turning totally brown. But the rain last week has stimulated regrowth of tender young shoots, so maybe that area isn't ready to be turned into raised beds after all. Darn!