Even sorrel roots (and so far I did not know that these things even worse than dandelions stuck carrots similar 30 centimeters deep in the ground!) Are not a problem - but then of course there's a crater that can not also of Gardena-Stecher avoid.
A long-term study is but how not mentioned - so if my part is the front butt now or in the middle breaks after 3 months, I can not judge.
... Supplement dated 08 August 2014: Even after 2 years of use still all good!