Most garden myths have some element of truth. Such is the case of the one that insists you can control field horsetail (Equisetum arvense), also called common horsetail, a very invasive weed, by applying lime. You actually could eliminate horsetail with abundant applications of lime… but you won’t want to. And here’s why:
The proponents of the “lime controls horsetail” belief insist that field horsetail grows only in acidic soils. It therefore seems logical that, if you make the soil more alkaline, it ought to make conditions hostile enough that horsetail would die out.
But the first bit of information was erroneous. Yes, horsetail does like acid soil, but it’s hardly exclusive to that soil type. It also thrives in neutral soils and does well even in moderately alkaline soils. (What it does like is moist soil, but that’s a different story.) It takes a very high pH (greater than 7.6) to seriously begin hampering the rampant growth of this common weed… but if your bring your garden soil to pH of 7.7 or above, you’ve essentially poisoned it: almost no garden plant you would think of growing could thrive in soil that is that alkaline! And I doubt if applying a “scorched earth policy” to your garden was what you had in mind!
Spread the Word
This myth about horsetail is still widely shared by well-meaning gardeners, even horticultural professionals. Yet anyone who has ever tried to control horsetail with lime can tell you it doesn’t work.
This is one garden myth that really deserves to die… so please don’t hesitate to share the real situation with your gardening friends.
How Then Can You Get Rid of Horsetail?
Actually getting rid of horsetail is no easy task, but here are some suggestions..