Nasturtiums are a popular edible garden flower with bright, cheery blooms and round leaves. Both the flowers and leaves of nasturtiums are considered edible and frequently used in salads or as garnishes. However, some people wonder – are nasturtium leaves poisonous? Let’s take a look at the facts.
The Short Answer
No, nasturtium leaves are not poisonous. Both the leaves and flowers of nasturtium plants are edible and safe for human consumption. In fact, nasturtiums have been eaten for centuries and are known to have several health benefits thanks to their nutrient content.
Nasturtium Leaf Uses
All parts of the nasturtium plant are edible, including the leaves, flowers, seeds and seed pods. Here are some of the most common ways nasturtium leaves are used in food:
- Salads – The rounded, bright green leaves add a pleasant peppery taste to green salads.
- Garnishes – Nasturtium leaves are frequently used as edible garnishes for dishes.
- Wraps – Large nasturtium leaves can be used like lettuce or cabbage leaves to make mini wraps.
- Pesto – The leaves can be blended into a flavorful pesto.
- Sandwiches – Young leaves work well as a fresh sandwich topping.
- Juices – Adding a few nasturtium leaves to vegetable juices provides nutrients and a spicy kick.
The flowers are also edible and make a beautiful, colorful garnish or salad ingredient. Nasturtiums were even used in place of capers before capers became easily available.
Nasturtium Leaf Nutrition & Benefits
Nasturtium leaves are not only safe to eat, they are nutritious as well. Here are some of the key nutrients and potential health benefits of nasturtium leaves:
- Vitamin C – Nasturtium leaves are packed with immune-boosting vitamin C. One cup contains about 60mg of vitamin C, which is the full recommended daily amount.
- Iron – The leaves provide a good amount of iron, an essential mineral that helps transport oxygen through the blood.
- Antioxidants – Nasturtiums contain carotenoids like lutein and zeaxanthin. These function as antioxidants that help protect eye health.
- Anti-microbial – Compounds in the leaves have been shown to have natural antibacterial and anti-fungal properties.
Some initial research also indicates nasturtiums may have beneficial effects on blood sugar regulation and cardiovascular health, but more studies are needed.
Are Any Parts of Nasturtiums Poisonous?
No parts of the common garden nasturtium plant (Tropaeolum majus) are poisonous. All sections of the plant can be safely consumed.
There are however a few closely related edible plants that should not be confused with nasturtiums:
- Watercress – Watercress is in the same plant family as nasturtiums (Brassicaceae). But unlike nasturtiums, some varieties of watercress may contain potentially toxic compounds if grown in polluted water.
- Amazon water lilies – Water lilies in the genus Victoria have edible seeds that are sometimes confused with nasturtiums. However, other parts of the water lily plant are toxic.
As long as you are using common garden nasturtiums (Tropaeolum majus) purchased at a nursery for culinary use, all parts are completely edible without any concerns of toxicity.
Historical Use as Food
Nasturtiums have been consumed for centuries and were commonly grown in old European herb gardens. Here is some background on the historical use of nasturtiums:
- Ancient Romans used nasturtiums frequently in their cuisine. They also believed the plant had medicinal benefits.
- European herbalists in the 17-18th centuries recommended nasturtiums for treating respiratory conditions and urinary tract infections.
- Nasturtiums were introduced to Europe from Peru where native Andean cultures like the Inca also grew the plant for food and medicine.
- In the 19th century, nasturtiums became popular garden plants and ingredients in salads across Europe and America.
- During WWII in England, nasturtiums were promoted along with other food plants to supplement rations and increase food security.
This long history of consumption demonstrates that nasturtium leaves have been safely eaten by humans for hundreds of years.
Uncooked vs. Cooked Leaves
You may come across some warnings about only eating nasturtium leaves cooked and not raw. Here are the facts:
- Nasturtium leaves contain a compound called glycosides that impart a peppery, spicy taste. Some sources claim these need to be neutralized by cooking.
- However, there is no evidence that glycosides in nasturtiums are toxic or harmful to humans when consumed raw. Plenty of people eat young, tender nasturtium leaves fresh in salads with no issues.
- Cooking the leaves does mellow out the spice. But eating them raw is not dangerous.
It comes down to personal taste preference. If you find the raw leaves too peppery, try cooking them briefly in soups or steamed dishes. But the leaves can safely be eaten either raw or cooked.
Purchasing Nasturtiums for Consumption
Since all parts of the nasturtium plant are edible, it’s easy to find leaves to use in your recipes. Here are some tips for purchasing nasturtiums:
- Buy nasturtium seeds or starter plants from a garden store – Make sure they are sold for culinary use.
- Pick your own – If you know someone growing edible nasturtiums in their garden, ask if you can harvest some leaves.
- Farmers market – Gourmet salad mixes at farmers markets often include nasturtium leaves.
- Online – You can purchase nasturtium seeds, living plants and even dried leaves from online retailers.
As long as the nasturtiums are sold for consumption purposes, the leaves will be perfectly safe to eat. Avoid picking leaves from public parks or other areas where they may have been sprayed with pesticides.
How to Harvest and Store Nasturtium Leaves
It’s easy to harvest nasturtium leaves for kitchen use:
- Pick younger, smaller leaves which tend to be more tender. Older large leaves may be tough.
- Clip the whole leaf and stem together right above the point where it attaches to the main stem.
- Rinse gently and pat dry with a towel or spin dry in a salad spinner.
- Use immediately or store in an airtight container lined with a paper towel in the refrigerator for 2-3 days.
To preserve nasturtium leaves longer, you can also freeze or dry them:
- Freezing – Blanch leaves for 1 minute, dry and freeze in airtight bags for up to 6 months.
- Drying – Hang bundles upside down or dry on a drying rack out of sunlight. Store dried leaves in an airtight jar.
potentially poisonous look-alikes to avoid
When foraging for nasturtiums, it’s important to properly identify the plant to avoid poisonous look-alikes. Here are a few harmful plants that should not be confused with nasturtiums:
| Poisonous Plant | Reason to Avoid |
|---|---|
| Deadly nightshade | Leaves, berries and stems contain toxic alkaloids |
| Foxglove | Contains cardiac glycosides that can cause heart issues |
| Lily of the valley | Toxic cardiac glycosides in all parts of plant |
Some key differences between these toxic plants and nasturtiums are:
- Nasturtiums have round, brighter green leaves while the poisonous plants have elongated or darker, duller leaves.
- Nasturtiums have brighter, trumpet-shaped flowers while these plants have bell-shaped or dangling flowers.
- Nasturtiums have a distinct peppery scent.
When in doubt, do not harvest wild plants to eat unless you are extremely confident in your identification and the plants have not been treated with herbicides or pesticides.
Nasturtium Leaf Recipes
Here are a few example recipes using edible nasturtium leaves and flowers:
Nasturtium Pesto
- 2 cups nasturtium leaves and flowers
- 1/3 cup walnuts or pine nuts
- 1 garlic clove, chopped
- 1/2 cup olive oil
- 1/4 cup parmesan cheese
- Salt and pepper to taste
Blend nasturtium leaves and flowers, nuts, garlic, salt and pepper in a food processor. Slowly drizzle in olive oil while blending. Scrape into a bowl and stir in parmesan cheese.
Stuffed Nasturtium Leaves
- 10 large nasturtium leaves
- 1 (8 oz) package cream cheese, softened
- 1/4 cup minced red onion
- 2 tablespoons chopped fresh dill
- Salt and pepper to taste
Gently clean nasturtium leaves and pat dry. In a bowl, mix together cream cheese, onion, dill, salt and pepper. Place about 1 tablespoon filling at the base of each nasturtium leaf. Gently roll up leaves from base to tip. Serve immediately.
Nasturtium Leaf Salad
- 5 nasturtium leaves and flowers
- Handful mixed salad greens
- 1/4 red onion, thinly sliced
- 1/4 cup crumbled feta cheese
- 2 tablespoons balsamic dressing
Place salad greens in a bowl. Top with nasturtium leaves and flowers, red onion and feta cheese. Drizzle balsamic dressing over the top and gently toss to coat.
Conclusion
Nasturtium leaves are not only completely safe to eat, they are highly nutritious and provide a pleasant, peppery flavor. Both the leaves and flowers of nasturtium plants have been consumed for centuries without any evidence of toxicity. Modern research shows nasturtiums contain compounds linked to health benefits like vitamin C, antioxidants and antibacterial effects. While the raw leaves pack some spice, cooking mellows out the flavor and makes them more palatable to some people. Overall, nasturtium leaves present an edible and tasty way to add nutrition, color and interest to your diet.