Stinging nettle (Urtica dioica) is a fast-growing herbaceous perennial that gets tall in the summer and dies back down to the ground in the winter. Erect stems growing 4 to 6 feet tall are lined with soft-green pointed leaves with serrated edges. While the flowers aren't showy, some gardeners appreciate the fact that stinging nettle serves as food for the larva of several butterflies, and when cooked, the leaves have a similar taste to spinach and are quite high in vitamins A and C and contain good levels of other nutrients.
Because of its ability to spread vigorously from underground stolons, burning nettle is considered an invasive species in much of North America—many gardeners are more likely to fight it as a weed than to plant it deliberately. But if you do wish to grow stinging nettle in your garden, plant it in the spring after the last frost. It is a fast-growing plant that will reach maturing by mid-season.
|Botanical Name||Urtica dioica|
|Common Name||Stinging nettle, common nettle, burning grass|
|Plant Type||Herbaceous perennial|
|Size||2–6 feet tall, 6–12 inches wide|
|Sun Exposure||Full sun to part shade|
|Soil Type||Any soil type|
|Soil pH||5.0 to 8.0 (acidic to alkaline)|
|Hardiness Zones||3–10 (USDA)|
|Native Area||Europe and Asia, but now naturalized everywhere|
|Toxicity||Causes severe skin reactions upon contact|
How to Plant Stinging Nettle
Stinging nettle is easy to plant by dividing of an existing patch of roots and planting the pieces where you want. Or, you can collect the seeds and sow them indoors a few weeks before last frost. As befits a plant with a reputation as a weed, stinging nettle is very easy to grow and has very few disease and pest problems.
This plant has a tendency to spread uncontrollably, which you can keep in check by removing the flowers as they appear to prevent self-seeding. Regular harvesting will also keep the plants in check. At the end of the season, the leaves and stems of stinging nettle make a good nitrogen-rich addition to the compost heap.
Stinging Nettle Care
Stinging nettle thrives in full sun conditions, but will tolerate some shade. Too much shade makes the plant grow too tall and leggy.
This plant does best in evenly moist, loamy soils rich in nitrogen and phosphorus. It often thrives in disturbed soil, which is why it is often found growing in abandoned lots and building sites, provided the underlying soil is rich. It tolerates a wide range of pH levels, from very acidic to very alkaline.
Stinging nettle has average water needs, and mature plants have a good tolerance for drought. If your region has regular rainfall (every two weeks or so), additional watering is not necessary.
Temperature and Humidity
Stinging nettle does well in all climate conditions across its hardiness range, USDA zones 3 to 10.
Nettles thrive on nitrogen-rich soil, so periodic feeding with compost or a nitrogen-heavy fertilizer will help the plants. But they often do quite well with no feeding at all.
Is Stinging Nettle Toxic?
The leaves and stems of this plant are covered with needle-like hairs that inject histamine and other chemical irritants into the skin of people and animals. Severe dermatitis reactions ensue. Reactions also can occur if you eat the plant without properly preparing it.
Symptoms of Poisoning
Skin contact with the leaves and stems of stinging nettle can cause a stinging sensation and may raise hive-like blisters on the skin. In most cases, the symptoms are only mildly to moderately uncomfortable. You can use anti-itch creams as well as antihistamines and anti-inflammatories, as directed by your doctor. However, some people and animals can have more serious allergic reactions, such as tightness in their chest or throat, that require prompt medical treatment. Severe cases can be life-threatening.
Stinging Nettle Varieties
There are six common subspecies of stinging nettle, but only five have the stinging barbs. They include:
- Urtica dioica subsp. afghanica: This plant is native to central and southwestern Asia, and it sometimes lacks the stinging barbs.
- U. dioica subsp. dioica: This nettle is commonly found in Europe.
- U. dioica subsp. gansuensis: This plant is found in China.
- U. dioica subsp. gracilis: Known as American stinging nettle, this plant is found in North America.
- U. dioica subsp. holosericea: Known as Hoary nettle or mountain nettle, this plant is found throughout western North America.
How to Grow Stinging Nettle from Seed
Stinging nettle is easy to grow from seeds collected from existing plants. The seeds are very tiny. Scatter them over the surface of a tray filled with ordinary potting mix. Press them lightly into the mix, and barely cover them with a baresprinkling of soil—they need some light to germinate. Keep the tray lightly moist until the seeds sprout, which happens within about 14 days. The seedlings can be transplanted outdoors as soon as the soil is warm enough to be worked.
Propagating Stinging Nettle
This plant is easy to propagate simply by digging up plants from an existing patch and moving them to a new location. This is easy to do in spring, when the plants are just beginning new growth. Stinging nettles spread readily through underground stolons, so new plants along the edges of an existing patch are easy to dig up and move. Wear gloves when handling the plants, to avoid skin irritation.
Harvesting Stinging Nettle
While all parts of the nettle plant are edible, the leaves and stems can’t be eaten straight from the plant due to the barbs. Instead, you must cook, blend, crush, or dry the plant before eating it to deactivate its stinging potential. If a person or animal does happen to eat leaves straight from the plant, this can cause reactions that are sometimes severe, including vomiting and trouble breathing.
Harvesting involves cutting back the top third of the plant, just above a node where leaves branch out. This will encourage new growth. The leaves will have the best flavor in cooking if they are harvested before the plant flowers. After this, the leaves because somewhat tough and stringy.
If you're working with a stinging nettle plant in your garden, always wear protective clothing. This includes thick gardening gloves, such as those made out of rubber, as well as long sleeves and pants. Avoid touching your face as you work.
How to Remove Stinging Nettle Plants
Stinging nettle can be difficult to remove from the garden, due to the plant’s toxic components. If you have a plant you need to get rid of, first moisten the soil around it to make it easier to slide out the roots. Then, don thick gardening gloves and protective clothing. Dig around the plant’s base to loosen the roots, and then grasp the plant at its base to slide it out of the ground with the roots as intact as possible. Finally, dig into the soil to remove any remaining pieces of root, as these have the potential to sprout new plants.
It’s helpful to have a tarp nearby that you can put your plant clippings on, so they don’t get lost in your soil or grass. Either compost them or seal them in a yard waste bag. Furthermore, to make sure new shoots don’t spring up, you can cover the site with a tarp or piece of cardboard for at least one full growing season. This will smother any new plants that try to grow.