Whether it’s winter chill or just a late, unexpected spring frost, tender plants need to be protected in sub-zero temperatures.
Wrapping Roses:
Most Roses grown in Canada require winterizing. This means that in the fall it’s best to mound each plant with good garden earth, or compost to a depth of about 12 inches, ensuring you cover the crown and parts of the canes. This is easily done by using a rose collar to hold the soil in place. Remove any remaining leaves and clean up all dead or fallen foliage. Climbing roses should not be wrapped, but carefully taken down, laid on the ground, and covered with mulch. As for Winter hardy roses, just leave them be.
Bring Plants Indoors:
Outdoor plants may not be at their best indoors, since they won’t necessarily get enough light, but they may make it long enough to survive through the winter.
Dig them up and store them:
Some tender plants, like geraniums, can be dug up and stored in a dormant phase until spring. Just pull them out of the earth, roots and all, and lay them in layers in a bushel basket in the garage. Cover with a blanket. Plant again in spring.
Build a Cold frame:
A cold frame is basically a greenhouse for an individual plant. Build a simple, temporary cold frame by bending slender metal rods into loops and sticking the ends into the ground across a garden row. Stretch clear plastic sheeting over the loops to enclose the plant.
Cover with a blanket:
Tucking in your plants works to combat late spring frosts that can kill tender young shoots. Throw down an old blanket, drop cloth, or landscape fabric. Remove during the day so that the plants can get light and air. You may need to weigh or tie down the cloth so that it doesn’t blow away.
Mulch:
Mulch protects plants by insulating them from wild swings in temperature, and helps in retaining moisture in the soil. Sometimes it isn’t the cold that damages the plant, but rather the repetitive soil freeze and thaw cycle affecting them when the soil is dry. Plus the freezing and thawing can prevent the plant from absorbing water and causes the soil to heave, or push the plant up out of the soil. Rake mulch away in the springtime to once again expose the plants.