Horsetail weed control

by Helen
(Orono,ON Canada)

Any idea on how to control horsetail weed or stop it in its tracks.
I have been carefully digging down and then gripping the main root, when I can,& gently try to follow it along to get all the other off shoots.
This is very painstaking, especially because they are ovetaking our asparagus bed & you have to be so careful digging in there. Any help would be appreciated. Thanks