Horsetail Identification, Risks, and Removal
Horsetail (Equisetum), often called Marestail (or Mare’s tail) is a deep-rooted invasive weed that is hard to control or remove. Find out what it is, and how to get rid of it.
Understanding Horsetail (Marestail)
Horsetail (Equisetum), often called Marestail (or Mare’s Tail), is a deep-rooted and notoriously persistent invasive weed found across the UK. With a fast-spreading underground rhizome network and seasonal growth that changes dramatically throughout the year, it can quickly overwhelm gardens, development sites, and commercial land.
Because it thrives in compacted, poorly drained soils and is resistant to most forms of amateur treatment, effective control requires professional expertise.
Below, you’ll find a complete guide to identifying Horsetail in every season, understanding its risks, and exploring your options for removal.
What Is Horsetail?
Horsetail (Equisetum) is one of the oldest surviving plant genera in the world, dating back over 350 million years. It is a highly adaptable and resilient invasive weed with a distinctive appearance that changes throughout the year.
Its hollow, jointed stems contain high levels of silica, giving the plant a rough, abrasive texture. Horsetail produces two separate types of shoots: pale brown fertile stems in spring that release spores, followed by green, brush-like foliage that emerges in early summer.
The biggest challenge with Horsetail is its aggressive underground rhizome network. These roots can extend several metres deep and spread horizontally beneath paths, roads, lawns, and foundations. This makes the species extremely difficult to control without a targeted, professional treatment programme – or excavation.
Identifying Horsetail in Spring
Horsetail first appears in early spring as pale brown, unbranched fertile stems that look almost mushroom-like. These shoots grow up to 30 cm tall and carry a cone-shaped structure at the tip containing spores.
These fertile stems emerge before the green foliage. They wither after releasing spores, typically by late April or early May, at which point the main vegetative growth phase begins.
Identifying Horsetail in Summer
During summer, Horsetail undergoes a complete transformation. The plant produces dense, green, branched shoots that resemble tiny conifer forests or bottle-brushes. These stems:
- Grow up to 60 cm tall
- Are segmented and jointed
- Often feature brown or black sheaths at each stem joint
- Form thick clusters that can dominate surrounding ground
This is the stage where Horsetail is most easily recognised and most likely to spread aggressively across gardens or development sites.
Identifying Horsetail in Autumn and Winter
As temperatures cool, Horsetail’s green summer growth begins to die back:
- Autumn: Stems yellow, turn brown, and break down gradually.
- Winter: Most surface growth disappears completely, leaving only brittle brown remnants.
Despite this seemingly dormant appearance, the plant’s underground rhizome network remains fully active. These roots can survive harsh winter conditions and will send up fresh shoots as soon as spring arrives.
Similar Species
Several plants are commonly mistaken for Horsetail. Knowing the differences is important for correct identification and management.
Great Horsetail (Equisetum telmateia)
- Less common than Field horsetail, Great horsetail has similar visual characteristics to Field horsetail but grows to a much larger scale, 0.3m-1.5m tall typically, rarely more than 2m tall.
- The sterile stems are thicker than Field horsetail with a darker more defined black frill leaf collar located at the top of the node above the base of the branches.
Mare’s Tail (Hippuris vulgaris) – the image shown
- An aquatic plant, found in ponds and waterways
- Unbranched or sparsely branched shoots
- Soft stems with no visible segments
Rough Horsetail (Equisetum hyemale)
- Taller, rougher, unbranched stems
- Often darker green with prominent ridges
- Common in marshy or wetland habitats
Horsetail Damage
Horsetail can cause damage to the environment, private land and hard surfaces, it’s also a blocker for construction projects. Here’s what a Horsetail infestation can lead to:
- Structural damage: Horsetail’s strong, deep rhizomes (underground stems) can infiltrate cracks in foundations, patios, and driveways, causing them to widen and break, potentially leading to costly repairs.
- Drainage issues: It can get into and block drainage pipes, causing water buildup and potential flooding.
- Garden and crop competition: It can take over gardens, suppressing smaller plants and competing with crops for nutrients and sunlight, which can reduce yields.
- Construction problems: It can damage newly laid surfaces, like driveways and footpaths, and requires removal before construction can properly begin.
Horsetail is also toxic to livestock, causing poisoning by inhibiting vitamin B1 production, which can lead to severe neurological issues and even death.
How to Remove Horsetail
Horsetail is one of the most difficult invasive weeds to eradicate due to its deep, multi-layered rhizome system and its resistance to most standard herbicides. Breaking or disturbing the plant often encourages further spread.
We recommend professional assessment for safe, effective control. Depending on the site, Environment Controls may use:
- Targeted herbicide treatment programmes
- Mechanical cutting and suppression
- Deep excavation of rhizomes
- Long-term monitoring to prevent regrowth
For reliable identification, treatment planning, or removal strategies, our invasive weed specialists can help you find the safest and most efficient solution.
Why choose us
- Residential & commercial Horsetail removal
- Fully qualified and certified
- Extensive in-house expertise
- National coverage
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