If you’re trying to get your site adopted by the council, but can’t due to an infestation of horsetail, this post is for you. We’ve recently been called out to a number of sites to deal with horsetail! Along the way, we’ve noticed that many developers are unsure what the next steps are for eradication, so here’s our guide on how to remove horsetail from site tarmac (and soft landscaping, of course).

Removing horsetail from your site

When developers ask what’s the best way to remove horsetail from site, what they’re really asking is: Do you have to rip up the tarmac? How long will it take? How much is this going to cost?   We get it. You’re at the very end of the project and the budget has receded like your old man’s hairline! Even worse, the council (highways) won’t take the site on unless the weed is eradicated, so where does this leave you?

Excavating horsetail

Excavating is the best way to remove horsetail from your site as it’s the most effective and the quickest. Unfortunately, it does involve breaking the tarmac and/or concrete and digging down into the soil. Usually, weed specialists will:

1. Strip the tarmac from all areas (and the top levels of soft landscape areas). 
2. Dig down through the soil until just above the services, removing all contaminated soil and debris and transporting it off site. 
3. Install a horizontal membrane across all areas. 
4. Make right the area, so reinstating tarmac, concrete, slabs, vegetation, etc. (Not all weed removal companies will offer this service, so check in advance!)
   

As you can see, excavating horsetail is a big job; however, it is the industry standard and the one we recommend. Our experience has also taught us that weed barrier membranes are worth their weight in gold and installing them is often the make-or-break difference between the council taking ownership of the site or rejecting it. If you need specific advice for your site, give our team a call.

Spraying horsetail

Spraying the horsetail with herbicides is also an option for development sites. The benefits of a herbicide programme are that you can keep your paths and established vegetation. It’s also much cheaper than excavation. The downsides to using herbicide is that it’s not guaranteed to eradicate the problem. Even with a dedicated 3-5 year spraying programme, we’ve found success rates vary and, because of this, councils are hesitant to take responsibility.

Spraying invasive weeds, like Japanese knotweed for example, normally works very well. However, the problem with horsetail is that it has a waxy layer on the outside, meaning it doesn’t take in herbicide very well, especially when it’s growing through tarmac.

What’s the problem with horsetail?

Like other developer weed nightmares, horsetail can also infiltrate and damage hard and soft landscaping, though thankfully we’ve yet to see a case of it actually growing through a house’s foundations like knotweed or bamboo. Sadly, many developers believe removing the top-most part of the plant will kill the entire thing, but that’s not the case. It’s also worth noting that horsetail is toxic to livestock!

Horsetail is not legally considered an invasive species under Section 9 of the Wildlife and Countryside Act 1981. So, legally speaking, you won’t have to lawyer up! The simple fact is, most councils these days are refusing to adopt sites affected by horsetail.

Horsetail vs mare’s tail

Even weed specialists get this wrong, so for the purposes of dealing with your site, all you need to know is that you’re almost certainly dealing with horsetail!

It’s horsetail, specifically common horsetail (Equisetum arvense), that will be growing through your concrete, not mare’s tail (Hippuris vulgaris), which grows in or near lots of water. 

Why the long face? Got horsetail? (Sorry, Dad joke.) 

Contact our team now on 0330 6781077.