Question
You guy's where very helpful the first time I thought I'd ask another question on my frustrated Nelly Moser. I live in NJ Zone 6 and my 2 year old Clematis bloomed a second time but now one vine has browned from the bottom up. The plant gets full sun but I keep the roots cool with mulch it looked great up until about 2 weeks ago it still has some flowers at the very top but the rest is brown and crisp. I fertilize with MG for roses about twice a month

Answer
Hi Marc,
Thanx for your question.  It's not unusual for clematis to turn brown at the bottom and remain lush and healthy from the middle to the top and sometimes just the top third.  You are correct to mulch the roots and keep them cool.  Your clematis are 2 years old and still need more time to build their root systems.  Another thing that will help is pruning.  Here is a link to instructions for pruning.  You'll need to identify which type of clematis you have and then follow these directions.

http://www.homeofclematis.net/html/pr_01.htm

I hope this helps.
Tom