By David Wagner

When a cold front swoops down the Willamette Valley, everything had better be prepared for it. For wild animals, it means having a source of food carefully stashed away and the ability to stay dormant until it warms up enough to dig up that stash. The most prominent to urban wildlife watchers are the nuts buried by squirrels and jays.

Out in the forests the mountain beavers have their hay stored underground. They cut their favorite herbage and spread it out to dry before hauling it into their dens.

For plants, there is no option for sudden reaction, no ability to quickly run and huddle underground. Their dormancy has been developing for a long time. The trees and shrubs that drop their leaves started forming winter buds in mid summer. By December, their primordial leaves have started to enlarge inside the buds, just like the embryos of pregnant bears hibernating in dens.

The herbaceous perennials have mostly retreated underground, often long before the cold season arrives. Many have their aboveground parts wither and vanish with the onset of the dry season. Their buds are on short stems that over winter at or below the surface of the soil. A thick mulch of leaves would be nice.

Then there are the perennial, evergreen plants. These are ones that keep their green leaves throughout the winter. Their leaves are tough enough to withstand freezing, yet stay alive and strong through early spring.  My favorites are the ferns, like the parsley fern.

David Wagner is a botanist who has lived in Eugene for more than 30 years. He teaches mosses and leads plant walks. He may be reached at fernzenmosses@me.com