Garden Life: Dormancy fleeting in Northwest winter garden

By Robb Rosser, Columbian Gardening columnist

Published:

 
photoRobb Rosser

Now that we have had a bout of real winter weather, our gardens should remain in a somewhat suspended state of dormancy for the rest of the winter season. I won't call it a permanent state of dormancy because experience in the Northwest garden has shown that dormancy in our part of the world is fickle, coming and going with the rise and fall of our temperate climate. We share this phenomenon with Britain and much of Western Europe, parts of the northeast United States, New Zealand, eastern Asia and southern Chile.

The hallmark of temperate zones is a relatively small fluctuation in temperature between seasons, with rain that generally falls year-round. However, some of these areas experience quite different types of weather depending on their position relative to the sea and winds. For example, although the northeast of North America is at the same latitude as western and northern Europe, it lacks the warming influence of the "North Atlantic Drift." As a consequence, much of the northeastern seaboard of the U.S. is icebound during winter months.

All this makes me happy we live where we do. Sure, the shorter days of winter mean less time in the day to spend outside. It's especially difficult when those days are colder and wetter than we might like. On these days, it takes me longer to get out in it. Once outside, it's tougher to sustain the effort to get any garden work done. I know that once I get started, I can always find something to do. The range of plants we can grow is directly related to the generally mild conditions and, as a consequence, there is a lot we can do outside in the winter garden.

Add layer of mulch

Since we might have periods of warming in the temperate winter garden, a layer of mulch should be applied when the garden is in the midst of a cold spell. By adding the mulch now, you are helping the plants remain in a state of dormancy for the duration of the winter. One of the reasons we lose plants in winter is that they come out of dormancy too early and are subsequently killed by a late season frost. The best way to insulate plant roots from frost is to cover the soil with an overcoat of compost. Even so-called hardy plants, such as hardy fuchsias and roses, benefit from an extra layer of protection around the crown of the plant.

This is, by the way, the easiest time of year to apply a layer of mulch. I'm convinced that one of the reasons gardeners don't mulch is because it's so difficult to know how to lay a cover of mulch when the garden is filled with plants. In winter, much of the plant material has died down to the ground and if you are ahead of the game, spent plant material has also been cut back. When borders are clear of plants, it's easier to spread a layer of mulch.

The best mulch you can use is homemade compost. It's inexpensive because it's created from plant material collected over the past year from your own garden. If you have collected it yourself, you can be assured that the material used in the making of the compost is clear and free of disease. Spread the compost two to four inches thick. At this time of year it's not necessary to dig it in to the ground. Once it's in place, worms in the soil will get to work recycling the organic matter, pulling it down to improve your soil.

Perennial plants with attractive seed heads or structural silhouettes, such as sedums and ornamental grasses, can be left to die down gracefully as part of the winter garden display. Many choose to save the job of cleaning up the winter garden until spring but if you wait too long, you risk damaging delicate emerging shoots. Besides, we all know that there is enough to do in spring without adding a job we could have taken care of in a less hectic season of the year

Our seasons do not begin and end distinctly. They typically meld into one another. Dec. 21 was the start of winter. It was also the shortest day of the year, so I remind myself that the turnaround has already begun. Every day grows longer from this point. However, for a while we have to accept the fact that it is winter. For me, the signal that it has really come is when I have to cover my neck and ears to stay warm. At least until I begin working in the garden.

Robb Rosser is a WSU-certified master gardener. Reach him at Write2Robb@aol.com.