Winter can put the frosting in the garden
By John Zvirovski, Sun Garden Editor
During the spring and autumn months, gardeners always pay close attention to the timing of the frosts. In the spring we watch for the last seasonal frost so we can begin planting our delicate new plants into the garden. During the autumn months we fear an early frost that ends the growing season too soon. Many of us pray for a late frost so we can enjoy the gardens for as long as possible before the winter season takes hold.
The development of frost on plant surfaces will kill the tissues of the plant causing it to die. Some light frosts of 30 to 32 degrees may singe the leaves but allow the hardier stems to continue to produce new growth in the weeks to come if it is not followed by repeat frosts.
Frost is visually more apparent during the late autumn months and during the winter season, as there is more accumulation for longer periods of time. Of course frost comes in many different forms depending on the air temperatures, levels of humidity and the surfaces it forms upon. As much as I dislike this natural occurrence during the growing season, I enjoy the crystallized displays later.
The occurrence of frost often happens when the surfaces which it forms upon are colder than the surrounding air. When humid air comes in contact with these surfaces, a frost formation occurs from numerous ice crystals. Since the crystals are clear and reflect all light, they appear white to the naked eye. When the frost formation is heavy, it creates a wonderful photo opportunity for amateurs and professionals alike.
Many different types of frost exist in nature depending on conditions. One of the most common frost formations is called hoarfrost. The creation of hoarfrost has produced many wonderful photographs for art exhibits, periodicals and nature magazines. It can make a spider web look like a shiny necklace of jewels or a delicate piece of lace work. Fine-twigged plants appear to have much thicker stems, and some of the most mundane of natural elements take on a glamorous appearance of their own.
Hoarfrost is typically formed on cold, clear evenings when the physical surfaces are cooler than the surrounding air. Radiant heat escaping at ground level rises into the night’s air, passing through these surfaces, which creates loosely-fitted ice crystals that gather and grow into needle-like structures, giving the objects a hairy appearance. These formations are very weak and can fall apart at the slightest breeze but are amazing to observe while calm. The word ‘hoar’ actually comes from an old English description referring to looking old — in this case the appearance of white hair.
Fern frost occurs on the inside of window surfaces when the outside temperatures are very cold and the indoor temperatures are damp and warm. The display of ferny frost can be altered by window pane anomalies such as dust particles on the surface, scratches in the glass or even small manufacturing defects. All of these elements can manipulate the frost formation differently each time it occurs.
White frost occurs when the humidity in the air is extremely high and moves through the air like an eerie fog. As it gently blows by all of the plant life and solid objects, it coats the surfaces with numerous ice crystals that thickly adhere en masse. Many of these frosts make evergreen trees look like they have been flocked overnight by nature. Oftentimes the density of the frost is so thick that when the sun comes out it almost looks like it is snowing as pieces fall from the trees.
As with any frosts that form outdoors, white frost gathers on surfaces that are opposite of the side the air moves from. When the breeze is stronger, the crystals will only form on one side with the lines going with the wind direction.
Although the many different types of frost that are created in nature are very beautiful, they can also be dangerous when traveling and when there is buildup on the roads. Always be aware that when frost exists on trees it may also exist on the roads to create slippery conditions.
The next time a frost comes to visit your garden during the winter, take a little time to appreciate some of nature’s magic and how it decorates every fine detail which it adorns. It creates a new scene within the garden that is just as enjoyable as the summer months. In many cases, this scene is more of the black and white genre with touches of evergreen here and there. Grab a camera and capture how the fourth season can transform your garden.