Remove white strip in mind maps using tikz

Question

Following the Tikz/PGF document, I am creating a mind map with 3 child nodes as can be seen in the MWE below. I want to remove the white strip in the connections between the node and the child nodes. There is a brief mention of the problem in the documentation, so I changed the decorations accordingly. However the problem still persists. Any advice?

MWE

\documentclass[tikz]{standalone}
\usepackage{pgfplots} 
\usetikzlibrary{arrows,shapes,backgrounds,fit,decorations.pathreplacing,chains,snakes,positioning,angles,quotes}  
\usetikzlibrary{mindmap} 
\usepackage{xcolor}

\pgfplotsset{compat=newest}

\begin{document}
\tikzset{level 1 concept/.append style={level distance = 22mm}}
\tikzset{every node/.append style={scale=0.5}}

 \tikz[mindmap,concept color=blue!60,decoration={start radius=1cm,
                   end radius=.5cm,amplitude=2mm,angle=20}]
  \node [concept] {Main}
child[concept color=red!60,grow=240] {node[concept] {Child1}}
child[concept color=green!60,grow=120] {node[concept] {Child2}}
child[concept color=orange!60,grow=0]  {node[concept] {Child3}};
\end{document}