We live in the Kawarthas and have a major problem with Horsetail or Marestail weed. I know it spreads on runners. Can you suggest a treatment that will reach these runners? Do you know of anything that will help to control this weed?
Our property was originally farmland. The area this grows in is covered in mulch. Sunny till about 4 in the pm.
The Field horsetail (Equisetum arvense) is a perennial that reproduces by spores (it is related to ferns) and by rhizomes. At the beginning of its growth cycle, fertile stems that are red-brown in colour appear, then disappear shortly afterwards, to be followed by sterile green stems. Control of this weed is very difficult since we are not allowed to use herbicides for cosmetic purposes in Ontario. Any disturbance to the root system stimulates the tubers to produce more rhizomes and stems. Any servered pieces of the rhizomes can give rise to a new plant.
The only strategy I can think of is to starve the plant into submission by cutting off all its above-ground stems whenever such appear, and introducing other plants to crowd it out.
If you are curious about the official take from the Ontario Ministry of Agriculture, Food and Rural Affairs, here is their article on Field horsetail.
Best of luck