border radius not apply inside container widget

Try this,
Use ClipRRect and nest inside another Container and now you can add non-uniform borders

Container(
                    decoration: BoxDecoration(
                      color: Colors.white,
                      borderRadius: BorderRadius.circular(10),
                      boxShadow: [BoxShadow(color: Colors.black12, blurRadius: 5)],
                    ),
                    child: ClipRRect(
                      borderRadius: BorderRadius.circular(10),
                      child: Container(
                        padding: EdgeInsets.all(20),
                        decoration: BoxDecoration(
                          border: Border(
                            left: BorderSide(color: Colors.indigo, width: 5),
                          ),
                        ),
                        child: Column(
                          mainAxisSize: MainAxisSize.min,
                          children: <Widget>[
                            Icon(Icons.home),
                            Text("Home"),
                          ],
                        ),
                      ),
                    ),
                  )