Horsetail (Equisetum arvense), often called mare’s tail, is an invasive, deep-rooted perennial weed that will spread quickly to form a dense carpet of foliage, crowding out less vigorous plants in beds and borders.


Quick facts

Common name: Horsetail, mare’s tail (misapplied)
Botanical name: Equisetum arvense
Areas affected: Beds, borders, lawns, paths and patios
Main causes: May establish from spores, but usually arrives via rhizomes from neighbouring gardens, or stem fragments in composts or manures
Timing: Seen in spring and summer; treat in late summer.

What is horsetail?

Horsetail is an invasive, deep-rooted weed with fast-growing

rhizomes (underground stems) that quickly send up dense stands of foliage. This page looks at options for gardeners when horsetail is becoming a problem. 



Horsetail is easily recognised by its upright, fir tree-like shoots that appear in summer.

In spring, fertile light brown stems, 20-50cm (10-20in) tall, appear with a cone-like spore producing structure at the end of the stems.

In summer, sterile green shoots develop into fir tree-like plants, 60cm (2ft) tall.

The problem

The creeping rhizomes of this pernicious plant may go down as deep as 2m (7ft) below the surface, making them hard to remove by digging out, especially if they invade a border. They often enter gardens by spreading underground from neighbouring properties or land.


The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner. 

Cultural control

Removing horsetail by hand is difficult. Although rhizomes growing near the surface can be forked out, deeper roots will require a lot of excavation. Shallow digging is not effective if it chops up roots, this can make the problem worse, as the plant can regrow from any small pieces left behind. However, removing shoots as soon as they appear above the ground can reduce infestation if carried out over a number of years.

If horsetail appears in lawns, it can be kept in check by mowing regularly.

Weedkiller control

The RHS does not support the use of weedkillers and recommends that alternative control methods are used. However, we do note that when gardeners struggle to control plants with cultural methods, regulated weedkillers/pesticides for home gardeners are available for use legally. Garden centres and large retailers selling weedkillers have trained staff who can advise on suitable products for your needs. Although, weedkillers available to home gardeners require many applications to achieve even limited control of horsetail.  

Weeds: non-chemical control

Join the RHS

Become an RHS Member today and save 25% on your first year

Join now

Gardeners' calendar

Find out what to do this month with our gardeners' calendar

Advice from the RHS

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.