Horsetail (Equisetum arvense) is common perennial plant that grows throughout the country. Quick to spread and difficult to kill, horsetail is one of the more annoying weeds to try and control in the garden. Even the smallest amount of horsetail can easily spread throughout your garden, as the roots spread far and wide while the plant reproduces using spores rather than seeds.
Traditional weeding methods such as mowing or slashing have little effect removing horsetail completely, as new stems develop from roots left behind, leaving many gardeners frustrated by their unwanted presence.
Problems with horsetail begin in spring when greenish brown shoots burst from the ground. These are tipped with small cones that produce spores that spread the plant even further, so it’s often a good idea to try and control them before they begin to spore.
However, as horsetail roots creep throughout the ground and are difficult to spot when working soil (mainly due to their brown colour), they usually spread much further than most people realise. Digging the roots up before the plant develops isn’t possible either, as the root systems go to depths of 1.5m – nobody is digging this deep in their garden to remove horsetail!
Once the stem has produced spores, horsetail develops small thin leaves throughout the plant, which last throughout spring and summer before dying off in late autumn. The roots remain intact though, so horsetail will reappear the next year and begin the cycle once more.
How to Get Rid of Horsetaill
While horsetail is very difficult to control it is possible to kill the weed before it develops into a larger problem.
Hoeing Before Spores Spread
Most importantly, you need to kill off the first stalks that produce spores to prevent them from reproducing and spreading further. Even though the stalks are likely to regrow, hoeing them out before they spore is an effective way to control their spread.
What Chemical Kills Horsetail
Horsetail leaves are surprisingly hardy, with the thin ‘tails’ covered in a waxy substance that makes certain contact weed killers virtually ineffective.
For instance, glyphosate is a contact herbicide that kills weeds by being absorbed into the plant through their leaves and foliage, yet the waxy horsetail leaves protect it against these types of weed killers. This may not be a bad thing however, as studies are revealing that glyphosate may be more harmful to people than we originally anticipated.
Neudorff Superfast and Long Lasting Weedkiller
Not all herbicides may be ineffective though! Neudorff Superfast and Long Lasting Weedkiller, made from pelargonic acid, maybe the best strong weed killer to better control the spread of horsetail. Pelargonic acid is naturally occurring in maleic acid hydrazide, which has been well-studied and used as growth regulators for vegetables like onions and potatoes since the 1950s.
To use this herbicide to kill horsetail, start by crushing the stems and leaves on the plant, which helps break up the waxy substance protecting it from contact killers. Doing so should make the herbicide easier to absorb.
This type of weed killer is easily available online and in garden centres and is completely safe after application. Pets and children can be around treated areas right after applying the herbicide, so it’s a safe option for anyone looking to remove horsetail from their garden.
Kurtail herbicide, a glufosinate-ammonium, is another option for killing horsetail. It may take several weeks to completely kill the weed, as the roots are log extensive that they take longer to die off – typically in 2-3 weeks. This herbicide is best-used when the horsetail is growing as it requires the weed to be actively growing to take effect.
Horsetail growing season is quite long though, so anytime between the start of March and end of September should suffice. The plant should therefore be allowed to grow to heights of around 20cm, as Kurtail works as foliar application, meaning it needs leaves to work.
Wait until the stem, leaves, and roots are completely dead before digging out the horsetail, otherwise the leftover root clippings will survive and shoot out new growth. Also, if you plan on using the dead horsetail for compost make sure to dry or drown them.
The product is designed for professional use so it won’t be as widely available as standard weed killers. Websites such as eBay do have regular listings of this herbicide however, so it should be easy enough to source it online.
It does degrade after contact with soil so the treated area can be worked with shortly after application. Sandy and peat soils may require longer before working though, so wait around 3 days for the herbicide to degrade in these types of soils.
Those seeking a non-herbicide method to control horsetail do have an option – although it may take a lot of weeding to get you the best results!
This process requires decent soil conditions (not overly wet) for forking out the soil to make dealing with shoots much simpler. With less soil, shoots are easy to remove, so cut off an inch below the soil surface each time they begin to shoot.
Because you’re limiting the growth of the plant, the root becomes deprived of food. Let it grow above 3-inches and the horsetail starts storing food at the roots once more, so never allow the shoots to reach above 3-inches!
Of course, this is merely a form of weed control as you probably won’t manage to remove all traces throughout the root systems. You do significantly reduce how much it spreads however!
Our lawn care tips article cover many of the most commonly asked gardening questions.