How to add the widgets dynamically to column in Flutter?

If you have the comments data already, simply create a List, then pass it to the children property of the Column. Something like:

var commentWidgets = List<Widget>();
for (var comment in comments) {
  commentWidgets.Add(Text(comment.text)); // TODO: Whatever layout you need for each widget.
}
…

new Expanded(
      child:
      new ListView(
        shrinkWrap: true,
        children: <Widget>[

          // Title

          new Padding(padding: const EdgeInsets.only(
              top: 10.00, left: 10.00),
            child: new Text(
              _feed.title, textAlign: TextAlign.start,),
          ),

          // content

          new Container(
            child: new Text(
              _feed.content, textAlign: TextAlign.start,),
          ),

          // Comments List will go here
          Column(children: commentWidgets,),
        ],
      ),
    ),

If you don’t have the comments data already and need to fetch it, use a FutureBuilder to build the UI once the future completes.