How to protect your plants in the winter
With the cold weather upon us sooner than expected. Many of us are thinking about having to winterize many of our outdoor things. Our boats our lawn mower adding snow tiers to vehicles. Many of us do not think about what we may have to do to protect our plants through out the winter.
There are several products online that are designed to help plants throughout the winter and many methods that have been written about but what is best for us here in the GTA. Canada is split into nine plant heartiness zones with zero being the harshest and 8 being the mildest. You can check your towns heartiness zones and history here but most of the Greater Toronto Area falls into heartiness zone number 6. With heartiness ratings, normally plants can survive one heartiness zone higher than where you live with proper care. Two above often these plants should be taken inside for the winter or they will have a high risk of not surviving. If you wish to have a very easy to maintain garden avoid plants that are two zones above and higher is a good Idea. In southern Ontario the plants that your landscaper installs or most plants at your nurseries should be fairly hearty for your area and will not require extreme care to be in order.
If you check online for methods to protect your plants those you should avoid are covering your plants in a plastic wrap. This can cause Sun scald as it can cause temperatures to increase significantly as the plastic can have a greenhouse effect. It can also cause plants to think its spring from the warmer temperatures. Plants produce chemicals to prevent them from freezing. The higher the heartiness zone the more chemicals they produce and the heartier they are. However, the warming can be interpreted as springs approach having plants down regulate these chemicals. Therefore, making them susceptible to the cold weather. This is why often times plants that survived the winter may all of a sudden die in the spring after a quick freeze. The other method you should avoid is soaking the roots, in warmer climates where frost is uncommon this is a good method for preventing the plants roots from freezing and additionally if you put a covering over the plants the warmer air released from the ground as it attempts to freeze will warm the leaves and stems preventing them from freezing. However here in southern Ontario flash freezes in the winter are not our main concern. With the extended cold the water will freeze around the roots which can cause rot. Most of the plants in our zones prefer drier roots during the winter.
For our plants since most of them area already relatively resistant there are only a few protection methods we would recommend. The first is to add mulch to your garden beds at least a few inches this will help insulate the plants from the cold weather especially before we have any snow protecting them or if we have a warm period during the winter. Along with mulching mounding around the base of some sensitive plants can be helpful as well. Such as roses they do well to have the grafted section of the plant well covered during the winter. This will be at the base of your rose bush.
Another protection we would recommend would be to tie up and cover many evergreens such as boxwood's, junipers and cedars. These plants in particular are susceptible to desiccation. Because these plants continue photosynthesis during the winter. They continue to release water through transpiration in their leaves. In the winter the air is particularly dry and with high winds it can easily dry out sections of the evergreen and with the roots frozen the plant is unable to bring more water up from the ground to replace the lost water. This can sometimes kill the plant but often times just killing off a section. Tying them up and covering them also protects them from getting misshapen by load caused by excess snow and or ice storms. Many plants will regain their shape after these events but many will not and it can be better to just avoid the problem by covering your plants.
If you don’t have time to cover your evergreens before winter or you notice some signs of winter burn in the spring do not fret. Simply cut back the plant to live wood and feed the plant with a fertilizer/ water mix and your plant should bounce back in no time.
Daniel Hogenbirk
Landscape Foreman
Birk’s Landscaping Inc.
(905) 404-0602
birks@rogers.com