My shutter speed was 1/6th of a second, and in this low-light environment of dawn, the only way to achieve a sharp background was to use a tripod. Don't think that, because your ultimate goal is a blurred image, you can get away without using the firm support of a tripod.
If your intention is to make the entire picture blurred, that's a different story. Then you can eliminate a tripod from the equation.
More on Jim Zuckerman...Jim Z teaches many online courses at BetterPhoto's digital photography school, including Techniques of Natural Light Photography, Developing Your Creative Artistic Vision, and Perfect Digital Exposure. Also, he contributed to these how-to books: The BetterPhoto Guide to Creative Digital Photography and The BetterPhoto Guide to Photographing Light.
Article by Jim Zuckerman. To learn more about photography, explore the many online photography and Photoshop classes offered here at BetterPhoto.com.