The temperature outside was not yet below freezing so I went ahead and watered all my plants with warm water, which then melted the snow around the base of the plant. After all the water soaked in I wrapped a small light blanket around the base of the plant. Then I placed a bucket over the top of the plants to protect from temperature drops this evening and from snow fall all day. I place bricks on top of my buckets because we are expecting high winds so I didn't want to have to go collect all my buckets from the neighbors yards later : )
This is my blueberry plant under the covering of a bucket with a light blanket wrapped around the base of the plant.
Plants that were too tall to be place under my bucket I watered with warm water, then wrapped a blanket around the base of the plant. Then I used plastic bags to cover the plants loosely. I have read that the plastic touching the plants can transfer freezing temps to the plant, but I am hoping the plastic will not be needed for an extended period of time and can soon be removed. Your goal is to create a pocket of air around the plant that is protected to some degree from the weather on the outside.
This is my Lilac wrapped in a towel and bags.
These are my Hyacinths, Daffodils, and Grape Hyacinths under a light blanket held down by bricks.
3-26-13 After leaving the bags on my lilacs from 9am Monday morning to 1:30pm Tuesday afternoon (so about 28 hours) the lilacs had survived the late snow, but there was quite a bit of condensation inside the bags. The parts of the lilac buds that were touching the bag had already started to rot a tiny bit. I think they will be fine with a little sunshine but, my conclusion is the bags worked well in protecting the plants for a short period of time. Ideally 12 hours is preferable and I'd say 24 hours is pushing it for damaging the plant. The buckets and blankets on the other hand I have left on plants in cold spells for 48 hours with no damage at all, because they are more breathable.