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Helping plants survive winter without protection

Make informed choices with regard to the hardiness of your plants, for example Heliopsis helianthoides, a native perennial
Photo: Jardin botanique de Montréal (Michel Tremblay)
Heliopsis helianthoides

Despite our harsh climate, you can avoid the need for a lot of winter protection by making informed choices when buying plants and choosing where to put them. It’s best to choose plants suited to your growing conditions and hardiness zone, and avoid:

  • placing a non-hardy plant in a spot buffeted by prevailing winds;
  • planting shrubs near a roadway where they will be sprayed with salt and covered in deicing salt or even struck during snow-clearing operations;
  • locating trees and shrubs in spots where snow and ice are apt to fall on them.

On the other hand, any microclimates on your property are ideal for less-hardy plants. Spots where snow accumulates naturally, that are protected from prevailing winds or less subject to frost in early fall or late spring are best.

Plants that don’t tolerate waterlogged soil when the snow melts in spring – alpine plants, lavender, sage, thyme, etc. – should be planted in very well-drained soil to reduce the risk of root and collar rot.

Good gardening practices

Some gardening practices can weaken plants’ natural cold resistance. For instance, feeding trees and shrubs with high-nitrogen fertilizer from mid-August to early October can encourage the growth of new stems that won’t have enough time to harden off before winter. Also, drastic pruning at this time of year can cause new tender shoots to appear.

But other practices can enhance their resistance. It is recommended that you water newly planted conifers regularly in fall for two years, to help them better withstand drying winter winds. You can usually tell when conifers need watering if the soil around them is dry to a depth of five centimetres.

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