One of the most impressive displays of ornamental grasses I have ever seen was in an estate garden where massive stands rose majestically as background plants and smaller tufts intermingled with broadleaf shrubs and perennials.
Each species was not only striking in appearance but welcomed as maintenance-free 51 weeks of the year, an important issue in a large garden. Not until winter did the grasses demand attention when they turned brown and brittle and needed pruning.
Handling dozens of tall clumps in this garden was easy enough for a hired professional, but for the home gardener, wrestling with large species doesn't always equate with easy care and low maintenance.
Many homeowners who have replaced lawns with ornamental grasses are surprised when their selections grow taller and wider than expected and pruning becomes a conundrum.
Deciding when to prune can be as simple as setting an arbitrary date or as complicated as waiting until grasses reach their ultimate golden beauty but before they are ravaged by wind and rain, broken into pieces and scattered.
The key is twofold — paying attention to color and to weather forecasts. As long as grasses remain mostly green and strong, they can withstand early storms; but by January, deciduous species lose color, stems weaken, and they begin to collapse. A series of storms blowing in off the Pacific can dash a dynamic scene before we're able to get outdoors.
In colder climates, gardeners leave tawny grasses standing throughout winter to peek out from under a coating of snow and lend an ethereal look to a stark landscape. They collapse in one spot and new growth doesn't begin until spring.
But without extended cold spells along the North Coast, most grasses here break dormancy as early as January and begin sending up new green shoots during the rainy season.
By delaying pruning, we lose the advantage of growth that may reach 12 inches tall, growth largely unseen when hidden inside dry, messy clumps. Timely pruning allows fresh shoots to develop into arching tufts before spring arrives.