Water plants don’t get much easier to grow than horsetail. Horsetail tolerates a wide range of soils and even grows in standing water. This plant has survived—and thrived—since prehistoric times. So, it’s not surprising to learn that horsetail is tough. The good news is it adds unique structure and texture to water gardens with its black-ringed, bamboo-like segmented hollow stems. The bad news is that horsetail is incredibly invasive, and it’s tough to eradicate. It is also considered toxic to horses, so use caution when planting it near areas where they roam.

That said, it’s the visual interest that horsetail adds to the landscape—even in the winter—that makes it worth the effort to control it.

Where to Plant Horsetail

Horsetail will thrive in both full sun or partial shade and it can tolerate almost any type of soil. Grow lofty horsetail alongside surface-hugging water lily and water hyacinth. You can also plant it in containers and enjoy its attributes in a confined growing location where it is less likely to displace nearby vegetation. Horsetail will provide a strong vertical accent in any of these locations.

The evergreen perennial is particularly well suited to water gardens, bog gardens, or trough gardens. It is perfect for covering a boggy area where nothing else works. It also looks striking at the edges of streams and ponds. In the wild, it is often found in marshes, bogs, floodplains, swamps, and other water-logged areas.

How and When to Plant Horsetail

If you are growing horsetail from seed plan to start your seeds approximately six weeks before the last frost. Seedlings or nursery-grown horsetail plants can be placed in the ground or planted in containers outside in early spring.

If you are planting horsetail in the ground, you can confine its growth by sinking a container in the soil (as you would for bamboo). Before planting, prepare your container (either above or below ground) by lining it with a sheet of fine mesh and filling it with sandy soil mixed with gravel. Dig a hole just deep enough to accommodate the roots of your plant and keep the top of the root ball at least 1 inch below the rim of the container. Fill in the remaining dirt and water profusely.

If you wish to plant your horsetail in water, spread a thick layer of gravel over the soil of a potted horsetail plant and submerge the container in your water garden. Make sure the pot is secure and will not tip.  

Horsetail Care Tips

Horsetail is a pretty, evergreen perennial that can flourish (sometimes to a fault) where other plants fail. It also requires very little maintenance aside from a consistent supply of water.

Light

Horsetail grows best in full sun if the soil is consistently moist but can easily grow in partial shade.

Soil and Water

Horsetail tolerates almost any type of soil but thrives best in sandy, gravelly, wet soil. It can grow in several inches of water but does not tolerate being fully submerged.

Since sandy or gravelly soil promotes rapid growth, when planting in a container, incorporate sand or gravel into a traditional potting mix. The more fertile and humus-rich the soil, the more slowly horsetail grows.

Temperature and Humidity

Horsetail plants love humid environments and can flourish in a variety of temperatures (from -15 degrees to 100 degrees Fahrenheit).  

Fertilizer

Fertilization is not required unless you are growing horsetail in very poor soil. If you feel you need to fertilize, feed your plants in the spring and summer with a water-soluble fertilizer designed for bog plants.

Pruning and Controlling

Prune horsetail regularly to control its spread and check it at least once a month for rhizomes that spread beyond (either under or over the edge of) the container. These rhizomes will typically appear in spring, but in fluctuating weather, they can happen at any time. Snip away rogue rhizomes or any fruiting stems to the ground and do not dispose of them in compost bins or near livestock.

Horsetail spreads rapidly when planted in the ground and will overtake nearby cultivated and wild areas. It spreads by underground rhizomes found up to 3 feet below the soil surface as well as spores that burst open and germinate in the soil. The most responsible way for most gardeners to grow horsetail is to plant it in a container, which will prevent the plant's rhizomes from spreading—but that won't stop the spores. The spores of horsetail plants have “legs” that can uncurl and crawl when humidity levels change allowing them to crawl or jump away.

Potting and Repotting

Like any container-grown plant, horsetail that is grown in pots can become root-bound if not tended. To avoid this, divide your plant every 3 to 4 years in the spring or whenever it looks too crowded in its container.  Dig up a colony of the plant and cut apart the rhizomes connecting the clumps. Horsetail is hard to kill, so don’t worry about damaging the root system. Plant your divisions into separate containers or dispose of unwanted sections by wrapping them in a plastic bag and throwing them away. Do not discard horsetail in compost bins, yard debris bins, or in areas where livestock feed.

Pests and Problems

Horsetail is both pest and disease resistant. In fact, horsetail (which has a high silica content) is so effective at repelling disease, it is commonly harvested and steeped in boiling water to spray on other plants as a natural fungicide.

How to Propagate Horsetail

Horsetail propagates easily on its own, so the best way to create new horsetail plants is through division. The best time to do this is spring, but any time between early spring and late autumn will also work. Just dig up the plant and cut away a portion of the rhizomatous root clump. You can replant the new division immediately in a similar container or another location.

It is worth noting that newly planted horsetail may take a year or two to acclimate before it begins to thrive. Don’t be tempted to add additional plants. Horsetail is known to flourish in some of the toughest conditions. Once the plant establishes itself, it will likely fill whatever space you have provided for it to grow (and sometimes well beyond that space).

Types of Horsetail

Common Horsetail

One of the most prevalent varieties of horsetail, Equisetum arvense is also known as field horsetail or common horsetail. It is native to the northern hemisphere and grows wild in nearly all climates. This type of horsetail grows from tuber-bearing rhizomes and is dimorphic—meaning it grows both unbranched, fertile, spore-producing stems and branched, sterile stems. It typically grows up to 2 feet tall with upright shoots that resemble bottle brushes.  

Water Horsetail

Often found in the standing water of lakes, marshes, and ponds, Equisetum fluviatile, is often called water horsetail, river horsetail, or swamp horsetail. It is a spreading perennial with thick, hollow, bamboo-like stems that feature whorls of black-tipped leaves at each node. Water horsetail reproduces both by spores and rhizomes and grows 2 to 3 feet tall in moist to wet soils.

Scouring Horsetail

With its tall, cylindrical, bamboo-like stems, Equisetum hyemale spreads aggressively through creeping rhizomes. Also known as scouring horsetail or scouring rush, this herbaceous perennial forms dense colonies that can grow up to 4 feet tall. Due to its dense growth habit, it works well as a container-bound privacy screen for patios, decks, and water gardens. It can be grown in hardiness Zones 4 through 9 and fares best in medium to wet soils with full sun or partial shade. The stems have a high silica content and were once used by early Americans to polish pots (hence its common name, scouring horsetail).

Giant Horsetail

Giant Horsetail (Equisetum giganteum) is native to Central and South America and—with a growth habit of 6 to 15 feet in height—is one of the tallest known horsetail varieties. It is second only to the Mexican Giant Horsetail (Equisetum myriochaetum), which can reach heights of 16 to 24 feet. It is hardy in warmer climates and produces narrow shoots that may not surpass an inch or two in diameter.

Companion Plants for Horsetail

Marsh Marigold

If you are looking for a companion plant to horsetail for a boggy landscape, marsh marigold can provide a welcoming splash of spring color. Also known as cowslip, marsh marigolds love moist, slow-draining soil and can often be found growing near the marshes, wet meadows, and swamps of North Carolina, Nebraska, and Tennessee. They are hardy in Zones 3-7 and can be found as far north as Newfoundland and Alaska.

Corkscrew Rush

Corkscrew rush (Juncus effusus) is an adaptable plant that thrives in various growing conditions, including dry and wet soil. It grows anywhere from 8 to 36 inches tall depending on the cultivar and is often found growing at the edges of (or slightly in) marshes.

Papyrus

Papyrus (Cyperus papyrus) is an easy-to-grow water-loving plant that is native to areas of Africa. It sends out grassy sprays of leaves that jut out from the stems like a fireworks display. It is easy to care for and easy to divide as the leafy clusters form plantlets that you can separate and grow individually. Grow papyrus in a weighted pot so that the stems rise above the water surface in a pond or grow it in moist soil at the water's edge.  Papyrus is hardy in Zones 9 and 10.