How can you rid of Equisetum Arvense?
Question:
I have Equisetum Arvense invading my lawn, flower beds, and rhubarb and blueberry patches. Last year, I very carefully cut the small plants off at the ground level and disposed of them in the trash. They have come back and are spreading. From what I have read, there is no easy (or any?) solution. You suggest acidifying the cranberry fields. Will that work? If so, how would I do that and what pH is good?
Answer:
Equisetum is a pretty little plant that can often grow innocuously, but when it gets established somewhere undesirable, it can prove quite a headache.
Because the plants you mention (lawn, flowers, rhubarb, and blueberry) have a range of pH needs, I’m hesitant to recommend a serious effort at broadly acidifying your soil. If the equisetum is largely in your blueberry patch, for instance, matching the soil pH to the acid-loving needs of that plant could work to mitigate the invasion (Equisetum prefers neutral to slightly basic soil), but your grass would not appreciate such an adjustment. Our colleagues at the Iowa State Extension recommend repeated mowing/cutting of the shoots to slowly starve out the plant, an approach echoed by the New York Botanical Garden, but caution that this approach requires patience and will take multiple seasons to see the impact. That said, there are very few plants that can survive indefinitely without access to the photosynthetic machinery of their foliage, so keeping them from producing leaves will eventually win the day. Avoid trying to till or pull out the equisetum, as the plant will resprout from broken rhizomes (the spreading underground stems).The same Iowa St resource discusses chemical control options, but many of those are approved for lawn/field use and not crop-bearing areas. This Univ of Wisc Extension study found chemical controls to be inconsistent and relatively ineffective. If you choose to go that route, please read container instructions carefully and follow them to the letter.