Broadleaf evergreens (boxwood) and mophead hydrangeas (H. macrophylla) two plants that I was reluctant to leave exposed to the harsh exposed winter conditions that they will experience in their home next to Lake Ontario. The drying winds combined with frozen ground (therefore unavailable water!) can leave boxwood descicated come Spring. Additionally, these particular hydrangeas bloom on old wood- that means, if their buds succumb to the winter conditions, then we can say goodbye to the 2015 blooms! Yikes!
While the burlap will not increase temperatures, it will reduce air movement around the plants and therefore decrease the drying effect of the wind on leaves and buds. Let's keep our fingers crossed!