Allotment - Marestail or horsetail is a deep-rooted perennial weed, very difficult to totally get remove from fruit and vegetables beds, although can be controlled. The root system of this weed can be over 2 metres deep.
I remove as much of the root system, I can, without disrupting the nearby vegetables root system. If the Marestail is growing next to the base of your 'grow your own' fruit or vegetable, then I tend to break it off a soil level and do this every week to keep control of the weed.