Ok, so I was pretty suspicious of the “let’s put down a blankie” idea for the garden before winter. If you have met me, you know that I am not the type of person who makes my own crackers. I buy them. In the garden, I will do fussy things but only if there is a good reason to do it. I resist babying plants and I resist doing things in the garden that make humans feel better rather than make an actual difference in the garden.
As I read studies about using winter mulch, I realized that the reason for mulch is not the COLD per se – the problem is temperature fluctuation, often from the sun’s rays. Cold is cold. The goal of bed covering in winter is not to stop freezing – it is to minimize the top layer of soil from warming up and cooling down. This freeze-thaw action forces smaller plants up and dislodges them from the soil surface. Now vulnerable and stranded, the plant’s roots dry out. (Ok, so I feel a little sympathy now …) Warming soil during midwinter thaws can also encourage plants to come out of dormancy in addition to being popped out of the soil surface by plummeting temperatures.
To assist your perennials (or more recently planted small shrubs) this winter, shade the soil around them to protect against the sun heating up the soil. Snow cover is the best winter insulator but is undependable – once we get snow, lightly push snow back onto beds when you can. Before the snow comes, we recommend adding 2-4 inches of chopped leaves, pine needles, salt marsh hay or sterile straw over the crown of the perennials and around the root zone after you have cut the perennials back and after temperatures are staying consistently in the 50-40F range.
More than just a comfort object, your garden’s ‘blankie’ of winter mulch will help keep it snug and minimize winter damage. Let us help you put your garden beds to sleep before the snow flies!