Boehmeria cylindrica aka False Nettle

Taxonomy ID: 5171

Boehmeria cylindrica, or false nettle, belongs to the nettle family. Other names include bog hemp and smallspike false nettle. Its native range spans North, Central, and South America. It reaches from southern Canada to Argentina and nearby countries. It grows in damp woods, marshes, wet meadows, and ditches. Some plants grow in shallow water within wet thickets.

This perennial forms upright stems and can make large clumps. Reported heights range from about 1.6–4.9 feet [0.5–1.5 metres]. Stems may branch, and some become woody and persist. The green stems can be round or four-angled. Their surface ranges from smooth to slightly hairy. Rough, simple leaves grow mostly in opposite pairs. Some leaves occur singly along the stem instead. Their shapes range from lanceolate to oval, with coarse teeth. Long, thin leaf stalks attach them to the stems. Each leaf has a main vein and two strong side veins. Unlike stinging nettles, this plant lacks stinging hairs.

Small greenish-white flowers appear from late summer into early fall. They lack petals and scent, and wind carries their pollen. Clusters form upright spikes where upper leaves meet the stem. Some spikes grow at the tips of stems. Male and female flowers usually grow on separate plants. Grow both sexes when seed production is the aim. Male flowers form spaced bunches along each spike. Female flowers make a more continuous line of bloom. The fruit is an achene that matures in fall. Its small, oval seed turns dark brown and bears hooked hairs.

In gardens, false nettle prefers light shade and moist, rich loam. The soil should drain well while retaining moisture. It also grows in full sun, where it needs wetter soil. Leaves may turn yellow-green in sunny sites. NC State lists it for USDA zones 4a–10b. Its British hardiness remains uncertain in the supplied evidence. It needs little upkeep and suits woodland or native borders.

Its main garden value lies in supporting wildlife. Eastern comma, red admiral, and question mark caterpillars feed on it. Mammals also browse the leaves. Fly larvae can cause spindle-shaped leaf galls. NC State reports no known diseases or insect pest problems. People have used stem fibre to make cord and nets. Plants For A Future lists no known food or medicinal uses. The lack of stinging hairs does not establish food safety.

Common names

False Nettle, Smallspike False Nettle, Bog Hemp, Small Spiked False Nettle, Stingless Nettle

More information about False Nettle

How easy is it to grow Boehmeria cylindrica?

Boehmeria cylindrica is a low-maintenance native perennial that requires minimal attention once established in a suitable site. It has no known pest or disease problems and is adaptable to a range of soil pH levels. The main requirement is consistent moisture — as an obligate wetland species, it needs reliably moist to wet soil to thrive.

What temperatures can Boehmeria cylindrica tolerate?

Boehmeria cylindrica is hardy across USDA zones 4 through 10, tolerating winter temperatures down to approximately -30°F (-34°C). As an herbaceous perennial, it dies back to the ground in winter and re-emerges in spring. Its native range extends from Quebec to Florida, demonstrating broad temperature adaptability.

What are the humidity needs of Boehmeria cylindrica?

As an obligate wetland species native to swamps, bogs, and marshes, Boehmeria cylindrica naturally thrives in high-humidity environments. It does best in humid conditions with consistently moist air, which reflects its natural habitat along stream banks, floodplain forests, and wet meadows.

Does Boehmeria cylindrica need fertilizer?

Boehmeria cylindrica generally does not require supplemental fertilization. In its native habitat, it grows in rich, organic soils along waterways and in floodplains where nutrients are naturally replenished. If planted in poor soil, a light application of balanced organic fertilizer or compost in spring can help, but over-fertilization is unnecessary.

Does Boehmeria cylindrica flower?

🌸 July-September

Boehmeria cylindrica produces tiny, greenish-white flowers in dense cylindrical spikes from the upper leaf axils, blooming from mid-summer to early fall (July–September). The flowers lack petals and have no scent, as they are wind-pollinated rather than insect-pollinated. Plants may be monoecious (both sexes on one plant) or dioecious (separate male and female plants).

How is Boehmeria cylindrica pollinated?

🐝 Wind

Boehmeria cylindrica is exclusively wind-pollinated. Its flowers lack petals and produce no scent or nectar, so they do not attract pollinating insects. The plant can be monoecious or dioecious — in dioecious populations, both male and female plants must be present for seed production. The small, hook-haired achenes that result are dispersed by attaching to passing animals.

How do you propagate Boehmeria cylindrica?

Boehmeria cylindrica can be propagated by seed or division. Seeds should be sown in spring in a warm greenhouse; germination benefits from consistent moisture. Division of established clumps is best done in spring and transplants easily. Note that dioecious populations require both male and female plants for seed production.

Can Boehmeria cylindrica be grown outdoors?

🇺🇸 USDA 4-10

Boehmeria cylindrica is strictly an outdoor plant, hardy in USDA zones 4–10.

Where is Boehmeria cylindrica native to?

Boehmeria cylindrica is native to eastern North America, ranging from southern Quebec and Ontario south to Florida and west to Texas and Nebraska. Scattered populations also occur in New Mexico, Arizona, and Utah. Beyond the US and Canada, it is found in Bermuda, Mexico, Central America, the Caribbean, and subtropical South America (south to Argentina, Paraguay, and Uruguay).

What pests and diseases affect Boehmeria cylindrica?

Boehmeria cylindrica has no significant pest or disease problems. NC State Extension reports no known diseases or insect pests. The gall midge Neolasioptera boehmeriae forms spindle-shaped galls on the stems, but this is a natural ecological association rather than a damaging pest. The plant's robust nature and lack of pest issues contribute to its low-maintenance reputation.

How does care for Boehmeria cylindrica change with the seasons?

As a herbaceous perennial, Boehmeria cylindrica dies back to the ground in autumn and re-emerges in spring. Dead stems can be cut back in late fall or early spring. The plant is fully dormant in winter and requires no care during this period. Active growth resumes in spring, with flowering from mid-summer to early fall. Ensure consistent moisture throughout the growing season.

Why are my Boehmeria cylindrica leaves turning yellow?

The most common cause of yellowing leaves on Boehmeria cylindrica is too much direct sun without adequate moisture. Illinois Wildflowers notes that in sunny locations, the foliage may become 'yellowish green.' Moving the plant to a shadier spot or increasing watering should help. Insufficient soil moisture in general can also cause yellowing, as this is an obligate wetland species that requires consistently moist to wet conditions.

What are the non-ornamental uses of Boehmeria cylindrica?

🔧 Rating 1/5

The primary non-ornamental use of Boehmeria cylindrica is fiber production — a tough fiber obtained from the stems has historically been used for cordage and nets. However, the fiber is considered inferior to that of its close relative ramie (Boehmeria nivea). Ecologically, it is valuable in wetland restoration projects and as a larval host plant for Eastern Comma, Red Admiral, and Question Mark butterflies.

What is the growth pattern and size of False Nettle?

⚡ Moderate
New growth will sprout from the top of the plant as it grows upwards.

What are the water needs for False Nettle

💧 Moist to wet
False Nettle should be watered regularly, allowing the soil to dry out between waterings.

What is the right soil for False Nettle

pH: Adaptable Medium loamy
When growing False Nettle, it is important to pay attention to the soil type you are using. This plant is very sensitive to dry soil and needs a potting soil that retains moisture. A good soil should still be well-draining and contain lots of organic matter. Coco coir or sphagnum moss are great options to provide the Smallspike False Nettle with the nutrients and moisture it needs. The added organic matter will also help the soil retain water and prevent the False Nettle from drying out too quickly. Before planting, make sure to mix compost or manure into the soil for extra nutrients. Also, make sure to water the Stingless Nettle regularly, making sure to keep the soil evenly moist but never soggy. With the correct soil and watering regimen, the False Nettle will thrive and bring lots of beauty to your home.

What is the sunlight requirement for False Nettle

To ensure optimal growth, the False Nettle prefers bright indirect light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.
Cat approves this plant

Is False Nettle toxic to humans/pets?

False Nettle is not known to cause harm to humans or pets.

More info:
Wikipedia • GBIF

Sources

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