In spring of 2004 I planted a tiny Italian Parsley plant in my herb garden. It survived the winter of 04/05, and came back strong in spring of 05, and provided lots of parsley all spring, summer and fall. Again, it survived the winter of 05/06 just fine, and came back strong again in the spring of 06, but all the sudden, a couple of weeks ago, this huge center stem came up from the middle like a tree trunk. Is this normal? Should I be concerned, or is this a good thing? Thanks.