Recently I came across this idea of resilience. That nature has the capacity to rebound from tremendous insults, given the chance to recover. Of course, if there are too many insults piled on for too long, as is the case with extinction, then resilience is impossible.
The idea has been in my mind as I look around the landscapes in our town following a record cold spell. We on the coast are particularly vulnerable when the temperature dips below freezing, and this time we were in the teens. Lows like this just don't happen often.
Where winter brings prolonged freezing, as in the Willamette Valley, folks take the time to "winterize" more diligently... water sytems, automobiles, and protecting half-hardy plants. On the coast it usually freezes in winter at least a couple times, but there is a difference between 32 and 17 degrees, particularly when it lasts a week.
Looking around your yard after this, you may be surprised to find survivors that looked beyond hope during the cold spell. In their attempt to survive, you will see plants take on a "wilted" look during the cold. This affectation limits one of the primary killers in freezing weather, desiccation. You may have noticed your rhodies taking on this sad pose in the cold, only to perk up once our warmer rains returned.
Desiccation occurs when the plant loses more moisture from the leaves (or needles) than it is able to take up from the soil. When the soil is frozen, roots may not have any water available. Meantime the dry cold air is wicking moisture from the leaves, which are warmed in the daytime sun. The damage is accelerated in windy conditions.
One of the lessons of the freeze then is to water in advance of the low temperatures. If a particularly cold night is predicted, be sure to water well the exposed plants that have leaves/needles (evergreens) and those in containers. This will give the plants a chance to fully hydrate and hopefully ride out the desiccating temps.
You may be surprised what plants will survive after such a spell. Give them the benefit of the doubt, wait until well into spring before ruthlessly pulling out prized shrubs that look sad. Gently scrape a small piece of bark to see if the tissue is green (or white) underneath, this indicates life. You can check several branches this way to determine what might need removal. Dead tissue looks dead.
Freezing weather can also provide us benefits for next season. Disease and pest levels are typically reduced when we have a good freeze. Small insects that are poorly adapted for winter and many fungal organisms will be killed, giving us a better chance for control next season. Look on the loss of a plant as an opportunity: most of us have little room for new selections, and the loss presents an opening.
It's only mid-December and there's a lot of winter left. Take the opportunity to assess your garden's vulnerability and prepare for the coming months. Then you can sit back and peacefully browse the new seed catalogs when the next cold spell arrives.