Every year I have problems with my holly plants. Last year, I purchased some small holly plants, and with our heavy snow got crushed. This year I purchased a much larger, $50 holly. It had beautiful red berries, but as the snow melted from the recent heat wave, I found that this too had been crushed from the snow. Unfortunately, it gets covered from snow that falls off of the roof. What can I do to prevent further damage to the plant?