HerbsEdible Plants

What Is Sour Grass?

Oxalis acetosella

When we think of sour grass, we think of Thai and Vietnamese soups and curries that have been expertly seasoned with this humble yet impactful herb.

From its vibrant leaves that transform your surroundings with its ornamental charm to its distinctively sour taste that enhances your favorite dishes, sour grass, also known as Oxalis or wood sorrel, has much more to offer than meets the eye.

If you’re a food enthusiast seeking to elevate your dishes with a tangy twist, a nature lover intrigued by its ornamental beauty, or an inquisitive mind curious about its traditional uses, you’re in luck.

Because in this guide, we’ll explore the history, health benefits, and many uses of this common yet remarkable plant.

What Is Sour Grass?

Sour grass, scientifically known as Oxalis, belongs to the Oxalidaceae family.

It encompasses a diverse group of plants, including annual and perennial species, with the most commonly encountered species of sour grass, including Oxalis acetosella, Oxalis stricta, and Oxalis pes-caprae.

Sour grass is native to various regions worldwide, including Europe, North America, and South America.

It thrives in different climates and soil conditions, making it adaptable to various environments.

Sour grass typically features clover-like leaves composed of three heart-shaped leaflets, although leaflet shape and size can vary depending on the species.

The leaves may be green or have reddish or purple tinges.

It produces delicate flowers, which can be white, pink, yellow, or other colors, depending on the species.

The flowers often have five petals and are held above the foliage on thin stems.

Although some species of sour grass are considered weeds due to their ability to spread rapidly and take over lawns or gardens, others are cultivated as ornamental plants for their attractive foliage and flowers.

Where Does Sour Grass Grow?

Oxalis pes-caprae
Source: Wikimedia

Here are the places where sour grass grows.


Sour grass can be found in mountainous regions, often in meadows or rocky areas.

It can adapt to various soil types, allowing it to thrive in higher altitudes.


Sour grass often grows alongside regular grass in backyards, featuring distinctive heart-shaped leaves and small yellow flowers.

Its tart taste makes it a popular choice for adding to salads or as a garnish for dishes.


Consider adding sour grass to your garden if you have a green thumb.

It can be grown in herb patches or containers.

Ensure it receives adequate sunlight and well-drained soil.

Farms and Fields

Agricultural areas and fields can host sour grass alongside crops.

However, farmers sometimes view it as a weed due to its rapidly spreading nature.


Next time you take a leisurely stroll in a park, keep an eye out for sour grass.

It tends to thrive in areas with partial shade and moist soil.

Coastal Areas

Sandy coastal regions create an ideal habitat for sour grass.

The plant’s ability to tolerate salty soil makes it a common sight near beaches and dunes, and its bright green foliage stands out against the pale sand.

Why Is Sour Grass Sour?

Oxalis stricta
Source: Wikimedia

Sour grass gets its sour taste primarily from the presence of oxalic acid.

Oxalic acid is a compound that naturally occurs in various plants, including sour grass, and is a key contributor to the tart and acidic flavor that characterizes this plant.

When you consume sour grass, the oxalic acid molecules interact with the taste receptors on your tongue, specifically the sour taste receptors.

This interaction triggers a response, sending signals to your brain that are interpreted as sourness.

This is why you experience that tangy, acidic sensation when you bite into or chew on sour grass.

What Is Sour Grass Good for?

Here’s what sour grass is good for.

Use #1: Culinary Purposes

Sour grass has many culinary applications, as its sour flavor adds a unique tang to dishes, salads, and beverages.

You can use the leaves and flowers as a garnish, incorporate them into salads, soups, sauces, and marinades, or make refreshing drinks, herbal teas, or even sour grass-infused vinegar.

Use #2: Natural Dye

Sour grass can be a natural dye for fabrics or Easter eggs.

The plant can produce a yellow or greenish hue depending on the specific variety and preparation method.

Education and Exploration

Sour grass can serve as an educational tool for learning about plant identification.

Use #3: Ornamental Uses

With its attractive clover-like leaves and delicate flowers, sour grass is often grown as an ornamental plant.

It adds charm and vibrant greenery to gardens, borders, or containers.

The leaves open during the day and close at night, giving them attractive, interactive quality.

Use #4: Medicinal Uses

Sour grass has been used in traditional medicine.

Some cultures believe it aids digestion, boosts immunity, provides antioxidant properties, and treats mouth sores or skin irritations.

However, scientific research on its medicinal properties is limited, so consult a healthcare professional before using it.

Use #5: Animal Forage

Livestock, such as rabbits, guinea pigs, or chickens, can enjoy sour grass as part of their diet.

The leaves and stems provide a source of nutrition and variety in their feed.


In conclusion, with its tangy flavor and diverse applications, sour grass offers a delightful and versatile addition to our culinary and botanical experiences.

But remember to consume it in moderation and be mindful of its oxalic acid content.

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