Don’t you love how snow brightens dark landscapes? In the garden, snow can benefit plants. But it can also cause severe problems. Let’s dig into how snow can harm or help in your garden.
BENEFITS OF SNOW
Insulates: Here’s a fun tidbit: The temperature under a layer of snow is usually warmer than the outside air. All thanks to the structure of snowflakes. Inside each crystal are hundreds of tiny air pockets encased in ice. And when snowflakes heap together on the ground, even larger pockets are created. The result is a fluffy, down quilt that insulates the ground. Without snow, prolonged periods of cold can spell trouble. Roots may be unable to take up water which means plants can die from dehydration.
Lets light in: While snow's whiteness reflects a certain amount of sunlight, a good portion of life-giving light penetrates the snow. Plants can continue photosynthesis through the winter, says local botanist, Stacy Studebaker. More on that later.
Collects fertilizer: Something magic happens when it snows. Sulfur and nitrogen compounds cling to snowflakes as they tumble to the ground, a 20-minute journey from the upper atmosphere. Then when the snow melts, these elements are released into the soil and are absorbed by plants.
Eases cold and colder: Freeze-thaw periods can be deadly to plants. It causes water in the soil to expand and contract, damaging roots, turning bulbs to mush, and even launching them out of the soil. A blanket of snow softens the blow of radical temperature swings.
Against the wind: Snow acts like a windbreaker, shielding plants from icy gales that suck moisture from leaves, stems, and roots.
Cushions containers: Snow-covered containers are less susceptible to cracking and splitting.
A lesson from trees: The next time it snows, go for a walk in the woods. Observe. Here, let me help. In a dense coniferous forest of cedar, pine, or spruce, 75 percent of a heavy snowfall collects on tree tops. Which means Meaning, little snow reaches the ground. No snow. No insulation. The ground can remain frozen well into spring.
On the other hand, when snow fall in a deciduous forest of cottonwood, most of it accumulates on the leaves and soil. Snow. Insulation. The ground remains warmer over the winter.
Back in the garden, I bet you can guess: The same thing happens. Let’s say you planted tulip bulbs and primroses under a spruce tree. Oops, the ground is often bare of snow. Roots, whole plants, and bulbs can suffer damage, especially during freeze-thaw periods.
Gentle moisture: If rain flows like a faucet, snow trickles like a gentle spring. Gradual thawing of snow, and to some degree, freezing, and thawing, improves soil texture, much like the burrowing action of earthworms, bacteria, and fungi.
Snow reveals mysteries: What creatures stroll around at night? Where does the soil warm first in the spring? Snow reveals animal tracks and helps us identify a garden's micro-climates. Watch how the wind deposits new snow and shapes existing drifts. Notice not just the passing of days, but where sunlight melts snow, first and last.
Natural bird feeder: Brown seeds stand out against the white of snow for birds and small animal to find.
What’s good about dirty snow? Ever noticed how snow turns to slush more quickly where the road grader created snow berms? When snow becomes dirty, it absorbs sunlight and melts more quickly.
Beauty of the season: In Kodiak, our day length at winter solstice is a mere 6.5 hours. I can hardly wait for the first snowfall. It brightens everything, creating peace and stillness which lifts everyone's mood. Especially Dan, who runs the local tire shop. In Japan, snow is revered in gardens and landscapes. Stone lanterns called Yukimi are added as snow-viewing accents. And snowflakes that adorn branches are called Sekka, or snow flowers. Google Sekka.
Christmas carrots: Every year, I gamble with my root crops, leaving them in the ground as soon as possible. Snow insulates the ground, buying time for me to dig leeks, beets, kale, and carrots. Sometimes I win. Sometimes I lose.
HARM CAUSED BY SNOW
You've seen trees and shrubs damaged by heavy snowfalls. Well, a thick layer of snow can also block sunlight which prevents snow warming from below and can delay emerging of bulbs and perennials in spring.
Keeping pests cozy: A blanket of snow protects not only your precious plants, but it also protects unwanted pests and diseases. Slugs, snails, molds, even aphids can overwinter quite nicely under snow.
Animals: Like a step-stool, snow gives rabbits, deer, and other creatures a leg-up to reach higher branches. This can mean double-trouble for the animal: I've seen photos of moose walking around Anchorage with Christmas lights tangled in their antlers.
Ice pools: When the snow melts slowly in the spring, it provides much-needed water to winter-thirsty plants. "But snow becomes a horror to plants when it thaws too quickly in the winter and forms ice pools around plants," says Master Gardener Deb Blaylock of Palmer. "The freezing and thawing of these pools are deadly to most plants.”
Which brings us to problem-solving:
PREVENTION IS THE CURE
Soil drainage: As Deb mentioned above, standing pools of icy water can be a problem. The solution? Improve soil drainage by adding compost, well-rotted manure, leaf mulch, bark chips, sand, sawdust, straw, or shredded seaweed.
Too much weight: Snow might be a great insulator, but too much of a good thing can break branches and trunks. Clear snow from greenhouses and sheds. I've watched with dismay as a slab of snow slid down my greenhouse roof and crushed a favorite rhododendron.
Tap trees, shrubs: As a child, I loved to traipse around the winter garden with a broomstick, tapping snow off plants. Bamboo especially. A quick slap sent a shudder through the stalks. They sat upright, dislodging the snow and showering me from head to toe.
Choose plants wisely: Would bananas grow in Kodiak? It's tempting to grow exotic plants in cold climates. In the long run, such gambles are a waste of time, money, and energy. Select hardy plants that are suitable for your micro-climate. Tip: Golden and variegated plants are often more tender.
Cover with branches: Each fall, I drape spruce boughs over my blue poppies, daffodil plantings, bleeding hearts, and other perennials. The branches provide a bonus layer of protection, especially in snow-free winters. At the same time, they allow light, air, and moisture to circulate freely.
Avoid chemical fertilizers: High nitrogen fertilizers such as Miracle-Gro encourage the growth of spongy, sappy, couch-potato leaves that are more susceptible to cold damage. Stick with organic mulch and compost.
Containers: Choose containers that are frost-proof. Avoid terra-cotta. Move containers into a shed, greenhouse or the leeward side of a building. Wrap with burlap, bubble-wrap to prevent damage to pot or plant.
Snow not only brightens landscapes, it offers a break from garden chores. And if you didn’t get around to cleaning up your foxglove stalks this fall, no worries. With snow, your neighbors will never know!
Coming up next week: Seed catalogs!
Marion Owen is a “Jill of all trades,” with 30 years of experience as a teacher and columnist. She’s on a mission to help busy people enhance their daily lives. How? She “Readers’ Digests” topics such as photography, cooking, and organic gardening. Get her free 4-page “In Good Light: Photo Tips for Busy People” to feel recharged when taking pictures. Go to Marion’s blog at MarionOwenAlaska.com.
Marion Owen is a "Jill of all trades," with 30 years of experience as a teacher and columnist. She's on a mission to help busy people enhance their daily lives. How? She "Readers' Digests" topics such as photography, cooking, and organic gardening. Get her free 4-page "In Good Light: Photo Tips for Busy People" to feel recharged when taking pictures. Go to Marion's blog at MarionOwenAlaska.com.