Hmm..I've had vari. periwinkle for more than 20 years (much to the consternation of the next door neighbors who also have to trim it back from their side of the hill) and it thrived through two severe droughts and weekly overhead watering from sprinklers. It still thrives in greater shade than ever before.

Pray tell how we might get the rain to fall from the bottom up so as to avoid overhead watering???

If yours died 'down' to soil level rather than died up from soil level I think you have a soil problem (be it drainage or soil compaction) or you may have voles or other soil denizens attacking from below.

Does your periwinkle location get adequate shade from the heat of the afternoon sun?
What was living in the soil (trees/shrubs etc.) before you planted the vari. vinca there?
If you had a pecan,hickory or worse..black walnut there you may have a juglone problem although it should have been evident soon after you planted.

Thanks for the help Dottie! I have heard and seen pictures of gardens that have beautiful success with vari. periwinkle. It's a really nice looking plant.

I figured that it was a soil problem as well. I think, although I could be wrong, that the soil is staying wet too long possibly?! I re-potted my periwinkle and changed soil in the pot. The plant gets some morning sun-early afternoon (9am-1pm) and then a break from the hot afternoon sun.

I am feeling a bit more hopeful for my little plant because since I have re-potted my periwinkle it's trying to put out new leaves on the surviving stems.

Woops. I read the post expecting it to be a plea for help in getting rid of it! It's lovely but easily a pest when planted in the ground.