Barred Horsetail Growing, Planting, Facts & Care (Equisetum japonicum)
Often commercially sold under the formal name, E. japonicum, this plant is actually a form of E. hyemale var. hyemale. It has grown in popularity as an ornamental due to its mesmerizing patterns and rigid features. Considered a modern-looking addition to gardens and aquascapes, barred or Japanese horsetail is a member of the Equisetaceae family. Its ancestors have occurred since prehistoric times, with features that have been well-preserved throughout the fossil record. Native to Japan, this bamboo-like variety is now a global favorite.
Barred horsetail is characterized by its bright-green stalks, which resemble reeds. Thick, dark-colored bars arise along the circumference of each node, giving the plant a distinctly ordered and cylindrical appearance. The leaves are largely inconspicuous to absent. When present, they occur as tiny growths along the joints, giving the bands a more organic finish.
The top of each hollow stalk tapers to a dull, sometimes ashy-colored tip. Flowers or seeds are absent as this species reproduces via spore production on strobili. It may also spread through the growth of underground rhizomes. At maturity, the stems reach an average height of about 3 feet (1 meter). Dense stands may arise in optimal conditions.
Facts, Benefits & Uses of Barred Horsetail
Barred horsetail can be grown as an emergent plant along the shallow margins or edges of an ornamental pond. The reeds can act as a protective maze for small fish and visiting amphibians, affording them protection. Interestingly, their submerged surfaces don’t serve as anchor points for biofilm and algae due to the production of antimicrobial and antiparasitic compounds.
As they can grow fairly tall, horsetail stems may need to be trimmed back to maintain their neat appearance. The cut reeds can be used in flower arrangements and can be propagated in water. They can also be grown in unique containers, like recycled bathtubs or hollowed-out logs, and arranged to create a stunning and highly textural backdrop. The stems occupy a narrow space due to the lack of fleshy foliage, so they are also great for lining walkways and vertical features.
Horsetail stems are known for being quite rough due to the presence of silica. As a result, they can be used as a crude alternative to sandpaper. The dried stems are great for scouring pots. They can also be treated with preserving chemicals for use in reed instruments. Barred horsetail would presumably have the same secondary metabolites, which are associated with diuretic and anti-inflammatory effects, as E. hyemale.
Barred Horsetail Growth, Hardiness & Climate
As E. japonicum can spread via rhizomatous growth, it can multiply quite aggressively in gravelly substrates. It is not at all a fussy plant when it comes to selecting sites for laying down new roots and stems. As it favors wet conditions, it can tolerate being grown in waterlogged soil and may even thrive in partial submersion.
This plant is a great option for the swampy areas of the garden or pond, where other plants may struggle to survive. If you don’t want it to spread too quickly, however, you may need to restrict its growth to within containers. Interestingly, it is somewhat averse to rich soil and may respond to an influx of nutrients with slow growth. Poor, relatively neutral soil is best.
Barred horsetail is highly adaptable to most types of light levels, but the stems do prefer filtered light or dappled shade. High humidity levels bring out their best features. If growing this plant in warm areas or outside of a water feature, it may need to be watered frequently.
How to Plant Barred Horsetail
As E. japonicum does not produce seeds, it is planted using its root ball or rhizome divisions. This can be obtained from mature plants with expanded root systems. If you’d like to spread the plant to other parts of the garden or pond, all you have to do is dig out a portion of the existing colony and transplant its roots, making sure to orient any existing stems in an upright position. You will seldom have to use cuttings to expand an existing colony, as the rhizomes will quickly colonize the free space around it.
To plant an intact root ball or rhizome cutting, first fill out a pot or container with a loamy or gravelly substrate. Dig out a hole that can comfortably accommodate the roots and bury them under approx. 2 inches of soil. Some horticulturists opt to plant barred horsetail in a container or pot, which they then bury in soil to give the illusion that the roots are unbound. This creates a more natural finish and affords a measure of control over the spread of roots. The same effect can be achieved with containers that are submerged along a pond’s margins.
Soil and water propagation using stem cuttings is possible as well. Make sure the cuttings have undamaged nodes, as the new roots are most likely to arise from these regions. If using soil, use a stick or your fingers to create holes for individual stem cuttings. The bottommost node should be buried under about an inch of soil. To get the stems to produce roots in water, all you have to do is make sure the bottommost nodes are fully submerged. Once these have produced roots, you can plant them in soil or grow them hydroponically.
How to Care for Barred Horsetail
E. japonicum is a low-maintenance cultivar that will not require much care or attention to grow profusely. In fact, more effort may be required to reduce or stop its spread. This is why cultivating this species in containers is recommended. If you find that your horsetail stands have grown too dense, you can cut some of the stems to the ground. This can even be done as soon as new stems appear.
To maintain the quality of your horsetail plant, keep its substrate moist throughout the year. Regularly check for moisture during summer to prevent the roots from drying out. This plant should generally be resistant to pests and diseases, but don’t hesitate to prune stems that look damaged. To maintain uniform coloration, remove any brown or dried stems.
How to Winter Barred Horsetail
Barred horsetail stems may begin to fade or die back as winter approaches. In milder climates, the stems tend to stay green all year round. Once you begin to see the stems dry out, you can cut them down to the ground. If they are grown in movable pots, you can relocate them to a warm, indoor location. Cutting the stems down shouldn’t hurt the plant, however. You’ll find that new stems will appear as soon as temperatures increase the following year.
In markedly cold or Arctic locations, you may have to place a generous layer of mulch around and over the crown of each stem. This will help retain moisture and prevent sudden changes in substrate temperatures for the roots. Remove the mulch in spring or as soon as new growths appear.
Is Barred Horsetail Invasive or Toxic?
As the parent species of E. japonicum, E. hyemale, is native to continents of the Northern Hemisphere, it is not considered an invasive species in North America or Europe. The barred horsetail variety is generally regarded as one of the less aggressive spreaders of its kind, despite its tendency to spread quickly. Nonetheless, in comparison to its near relatives in the Equisetum genus (e.g. E. arvense), it is more easily controlled. Note that even rhizome fragments can eventually generate colonies that herbicides may struggle to eradicate.
If you’re concerned about the spread of this potential pest plant, don’t forget that there are measures you can take to restrict its roots. You may also deadhead the terminal strobili before they can release their spores. If your property is home to domesticated animals, keep in mind that all of this plant’s tissues are toxic. Horses are reportedly the most vulnerable to the toxins of Equisetum species.
Is Barred Horsetail Edible? Do Animals Eat it?
As this plant is practically leafless and has hollow stems, it doesn’t have much consumable material to begin with. It cannot be used as a type of food due to its toxic profile, but it does have some pharmacological applications.
Some Russian and Eastern European cultures have used horsetail as a folk remedy for a wide variety of ailments, including ulcers and bladder problems. Specifically, the E. japonicum variety is more utilized as a polishing material rather than a source of medicinal extracts. The toxic plant parts are rarely ever consumed by animals.
Where to Buy Barred Horsetail & Seeds? (UK & US)
Equisetum japonicum (often sold as E. hyemale) can be purchased as bare root or potted plants from garden centers and aquascaping stores throughout North America and Europe. If located elsewhere, you’ll need to check your locality’s list of prohibited plants before making an online purchase. If E. hyemale is restricted, this variety will most likely be restricted as well. Consider investing in non-invasive or slow-growing alternatives instead.