For the past two years, we've had to throw away a lot of dead lilacs in May and June. We've done something different this year. Instead of leaving the pots out in the nursery area, we tipped them on their sides in early December. It was a mad dash one weekend, because it was going to snow on Sunday and I was going out of town the following weekend. We tipped them over in rows and covered the entire section of pots with white overwintering film, on the advice of a wonderful lilac expert I know who has grown in Massachusetts and New Hampshire. The pots were well-watered and the potting mix was frozen when we covered. This will help keep the plants at a more consistent temperature over the winter and protect them from drying winds. The past two years we have had early thaws - it was 80 here last February - followed by hard freezes. This damages the plant tissues and makes the plants susceptible to lilac blight. After tossing hundreds of plants for two years in a row, we decided to try covering. If it gets warm, we can open the sides of the "package", and when it cools down again we can close it up again. Let's hope this helps the plants to be in better condition when we open in April!