We too, here in Northern Illinois, experienced a warmish March followed in April by cold days and many very cold nights (low 20's). My early daffodils were buried in heavy snow which then cracked off the emerging blossoms and my middle tulip shoots were blown flat by cold winds and then frozen solid. This week I have noticed that the other late spring bulbs are coming up and looking good. My dead looking viburnums have green shoots and the hostas have grown 3 inches in one day. My shrub roses are sprouting way down the cane and my climbing rose looks dormant (dead) yet. My neighbor's gorgeous star magnola
blossoms frooze, turned brown, fell off and the smaller secondary buds are now opening. I am sitting tight and trying to be patient. I expect some damage and will not rip anything out until mid summer. Our forecast is for 80 degrees this Sunday. What a climate!