Got Snow? Don’t Worry – Your Garden’s Okay

This past week has been full superlatives when describing the snow that has fallen – unprecedented and disastrous (Hello, Texas), unlike anything they’re used to (Hello, Seattle), etc. For millions of Americans, this is something they’re not accustomed to, and that alone can be scary. For others, snow is a regular visitor in the winter, but this year there’s been so much more of it than usual. The snowfall is unusual all over –Russia is staggering under their massive amounts (more here) and Saudi Arabia has been uncharacteristically hit (see some bewildered camels here ).  It’s enough to worry anyone who’s been looking forward to a spring garden.

The truth is that snow is not as disastrous for a garden as it may seem at first glance, although it does carry some risk. Let me lay it out in pros and cons:

PROS – 

• Fresh snow works like a cozy blanket as it covers plants. Snowflakes contain tiny pockets full of air, and when they accumulate on the ground they heap together and form larger and warmer air pockets. This air can prevent the soil from freezing and allows roots to continue thriving and taking up water to supply the plant. This is especially true in those areas where sudden low temperatures are not expected to last a sustained amount of time.

• Snow forms a barrier to keep drying and damaging winter wind from bark and delicate plant leaves. 

• A layer of snow can protect a plant from the worst effects of the freeze-thaw phenomenon. This is when ice causes the ground to expand when it freezes and constricts when it thaws. The end result of this can be favorable for the soil by creating a lighter, more friable soil that new plants in spring and overwintering bulbs will appreciate. In the worst case, freeze-thaw can turn bulbs into mush and uproot plants. A layer of warming snow can reduce this likelihood.

• Snow holds water in the soil and, as it melts, it slowly waters the area. This is especially beneficial for emerging perennials. 

• There is an old saying that snow is “Poor Man’s Fertilizer”, and, like many old sayings, it turns out to be true. As snowflakes make their long fall down to earth they accumulate nitrogen and other micronutrients along the way. These elements are then slowly released into the soil as it melts. Even dormant plants can absorb nitrogen deposited in this way.

• Snow can enhance the sunlight given to plants. The brightness of the snow causes light to shine all around and even down through it so that plants can continue to photosynthesis through the darkest months of winter. 

• Snow cover can hide the egg cases and chrysalis of many beneficial insects and moths and protect them from predation.

CONS – 

• The weight of snow on branches and small trees can quickly become too much for them. Branches can split or break off entirely, and trees can collapse or uproot. To avoid this, clear snow off your growing things as soon and as often as possible. Don’t forget to clear it from the roofs of any structures that are next to your trees and plants. A mini-avalanche from your garage roof onto your landscaping along your house could be tragic. 

• As the snow melts, watch for ice pools that can form around trees and plants. If the temperature falls again, you can find yourself in that freeze/thaw cycle that many plants cannot recover from. If you see this happening, you’ll need to get out there and get some drainage going. If you have to make some furrows where there weren’t any before, don’t hesitate. As long as you keep your plants alive, you can tweak the aesthetics later. Now that you can see how winter affects your garden, this would also be a great opportunity to develop a better year-round garden plan, with plants’ placements that suit their needs all year round. 

• Snow creates cover for hungry animals like voles, who work underground, but also serves as a step up for those that prey on bark, branches, and leaves. When the snow hides their close-to-the-ground food sources, those lighter creatures can easily scamper up it to feast on plants. Be watchful for tell-tale tracks and take gentle steps to keep them away from your plants.

• In areas where there was drought the previous summer (which is almost everywhere nowadays), trees and shrubs that go into winter drought-stressed may have little left to fight off the cold. While there is little that can be done once the cold has arrived and the snow has fallen, this should be a reminder to prepare your plants for tough winter weather by first preparing them to get through a tough summer. For more on this, check out this article.

• Snow can provide a safe place for beneficial insects but is also works to protect less desirable entities like snails, slugs, overwintering insects, and molds. Keep a careful eye on what emerges not just after the snow, but as everything truly warms up in spring. Remember that early and pro-active treatment of pests and pathogens is the most effective treatment overall, so an early problem does not have to develop into a mid-season infestation. 

The effects of a snowstorm are considerably different than an ice storm. There is not a whole lot of positive to be found after one of those (read more here). So, as much as you are able, if you’re only dealing with snow try to enjoy it while it lasts. And if you want to keep the kids busy, send them out to knock some snow off the trees.

Stay Warm.

                  Submitted by Pam                   

The World of Winter Trees

Winter may seem like a dead time for tree lovers, but there really is a lot going on in the world of trees at this time of year. For trees, this is just another part of their yearly cycle. There are particular trials for winter trees, but also a lot happening out of sight. Evergreens have their own way of doing things in winter, but for the purposes of this blog, I want to explore the cold-weather life of deciduous trees.

Trees begin preparing for winter months before cold weather and snow move in. Part of the transition is one that we can all see and appreciate, the magnificence of autumn trees. Green leaves contain chlorophyll, which not only gives them their color, it also feeds the tree through photosynthesis. During the winter trees will live off the food they have stored in the summer, so they will not need their leaves. They stop making chlorophyll, the green color disappears, and latent colors appear. The colorful leaves soon fall off entirely, relieving the tree of the need to provide the water and the mechanics of photosynthesis that leaves require. The tree is then able to focus its resources on its other parts. Losing their leaves is one way trees protect themselves ahead of winter dryness. They also move water around in their cells to protect them from freezing and to keep their nutrients intact. Read more on this here.

Water is a big issue for trees in cold winter climates. They cannot depend on the soaking rains from other times of the year, and when moisture does fall it is often bound up in snow. Moisture is moisture, one might think, but frozen water is very difficult for trees to access. If you are tending trees, water them when temperatures are above 40°F and there’s no snow, and use a product like Hydretain that holds water in the root zone. Here’s an article on watering trees at this time of year from the city of Greeley, Colorado, where they know a thing or two about winter weather. 

Water is at the root of another problem for winter trees – the risk of exploding. Although it sounds very dramatic and catastrophic it is only one of those things. Trees can make a sound like a gunshot, which is definitely unsettling, but this phenomenon does not cause the tree to experience a bomb-like phenomenon. They crack (both physically and audibly) instead. This is caused by water freezing and expanding inside the tree (more on the science of it here), creating a rupture in the bark of the tree. This sort of thing happens in sub-zero weather in areas where native trees are winter-adapted, so they are generally able to shake off such cracking (more here). Check out this video, to see an “explosion” for yourself. 

Internal ice is not the only thing that poses a problem for tree bark. Sunscald (sometimes called Southwest Winter Injury) can get them, especially if they’re younger trees. Sunscald happens when there are warm, sunny days and then cold winter nights. During the day the sun heats up the bark, causing the cells to open up and activate in response. Once night falls, freezing temperatures can damage the newly-opened cells. The end result can be bark cracks and even damage to the wood underneath the bark. There’s not much you can do once this happens, but proactive treatments include wrapping the tree or applying protective paint. We carry both wraps and paint. 

Wrapping a tree not only protects it from sunscald, it can offer some protection to the bark from animal damage. During the fall and winter, all sorts of critters want to feed off of, rub onto, or otherwise prey on your trees. Here is a brief article from the Chicago Tribune that explains the most common animal culprits and ways to ward them off. If you didn’t get around to wrapping your tree, or you didn’t want to, or if you did and want more protection, animal repellents can add another layer of care for your trees. We have a variety of great repellent products (see here) that can help with whatever is pestering your trees without resorting to toxic chemicals. 

Tibetan Cherry Tree 

Damage from weather or animals aside, bark can be a compelling sight on a winter tree. Some trees undress just enough in the winter for you to see the pretty wood they are hiding under their bark. There are those that hide their beauty behind their foliage and there are those that exfoliate their outer bark in winter and surprise you with the beauty beneath. Here and here are some gorgeous examples.

Despite all the hardships that the season can bring, trees do a lot of work in the wintertime. It’s just doing all the work out of sight underground, so it is hard for mere humans to observe and appreciate their efforts. This article explains (as well as scientists can determine) what’s going on down there in the root world. Basically, their goal is to spread out and strengthen before spring comes so that they have the resources they need for robust aboveground growth. This plan seems to work most of the time, unless there is an exceptionally hard frost that penetrates deep into the soil or the soil is disrupted by frost heaving. Frost heaving occurs when soil freezes and the ice moves towards the surface. This can weaken trees to the point where they are unable to stand. Fortunately, for all this to happen a number of variables have to come together, and for the overwhelming majority of trees, this will never be an issue. So, they are free to keep on developing their roots in pursuit of the perfect rhizosphere. 

Trees are our priceless companions on this planet. They are sources of life-giving oxygen, but also life-affirming joy and beauty. As we head into a new year, let’s all resolve to appreciate and protect them.

Stay warm and stay safe out there. 

Submitted by Pam