Question
I live in the Pocono region of Northeast PA.  Our last frost date falls between 5/16 to 5/30.  This past winter I hilled earth around the base of my tea roses after trimming them back, and then placed oak leaves in a wire cage wrapped in burlap.  When should I begin to uncover my roses?  Should I do it gradually, (ie. remove burlap, then leaves, then earth mound)or just all at once?

Answer
Sounds like you have protected your teas perfectly. Teas are hardier than most people give them credit for but you don't want to take any chances with them as some may be more tender than others. As you said, the burlap is the first to go and that could be done when temperatures are above freezing at night say in the beginning of May. Wait for a week and then pull the leaves away from the base. If by then the weather appears to be totally frost free then you can clear away the soil from the base. Should you get a  frost in May, it will be one that doesn't last and so will not hurt the rose bushes. Roses can withstand frost if it is only for a day but when it runs for three days then damage can be done to the rose canes.