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Hoary Mustard

Hirschfeldia incana

Please keep in mind that it is illegal to uproot a plant without the landowner's consent and care should be taken at all times not to damage wild plants. Wild plants should never be picked for pleasure and some plants are protected by law.
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Plant Profile

Flowering Months:
Brassicaceae (Cabbage)
Also in this family:
Alpine Pennycress, Alpine Rock-cress, American Wintercress, Annual Wall Rocket, Austrian Yellowcress, Awlwort, Bastard Cabbage, Black Mustard, Bristol Rock-cress, Charlock, Common Scurvygrass, Common Whitlowgrass, Coralroot, Creeping Yellowcress, Cuckooflower, Dame's-violet, Danish Scurvygrass, Dittander, Early Wintercress, Eastern Rocket, English Scurvygrass, Evergreen Candytuft, False London Rocket, Field Pennycress, Field Pepperwort, Flixweed, Garden Arabis, Garden Candytuft, Garden Cress, Garden Radish, Garden Rocket, Garlic Mustard, Glabrous Whitlowgrass, Gold of Pleasure, Great Yellowcress, Greater Cuckooflower, Greater Periwinkle, Greater Swinecress, Hairy Bittercress, Hairy Rock-cress, Hairy Rocket, Hairy Whitlowgrass, Hedge Mustard, Hoary Cress, Hoary Stock, Hoary Whitlowgrass, Honesty, Horseradish, Hutchinsia, Hybrid Watercress, Intermediate Periwinkle, Isle of Man Cabbage, Large Bittercress, Lesser Swinecress, London Rocket, Lundy Cabbage, Marsh Yellowcress, Mountain Scurvygrass, Narrow-fruited Watercress, Narrow-leaved Bittercress, Narrow-leaved Pepperwort, Northern Rock-cress, Northern Yellowcress, Oilseed Rape, Perennial Rocket, Perennial Wall Rocket, Perfoliate Pennycress, Pinnate Coralroot, Purple Rock-cress, Pyrenean Scurvygrass, Rock Whitlowgrass, Russian Rocket, Scottish Scurvygrass, Sea Kale, Sea Radish, Sea Rocket, Sea Stock, Shepherd's Cress, Shepherd's Purse, Small-flowered Wintercress, Smith's Pepperwort, Steppe Cabbage, Swede, Sweet Alyssum, Tall Rocket, Thale Cress, Tower Mustard, Treacle Mustard, Trefoil Cress, Turnip, Wall Whitlowgrass, Wallflower, Wallflower Cabbage, Warty Cabbage, Watercress, Wavy Bittercress, White Mustard, Wild Cabbage, Wild Candytuft, Wild Radish, Wild Turnip, Wintercress, Woad, Yellow Whitlowgrass
Life Cycle:
Biennial or Perennial
Maximum Size:
90 centimetres tall
Roadsides, wasteland.

Yellow, 4 petals
A spike of pale yellow flowers. The similar looking Black Mustard (Brassica nigra) has flowers which are not as pale as those of Hoary Mustard.
A 2-sectioned, waisted pod.
An annual flower, similar to Black Mustard (Brassica nigra) which has pinnately lobed lower leaves and upper lance-shaped leaves. Hoary Mustard differs in that the leaves are a paler green and its lower leaves and stems are covered in coarse whitish hairs. Pollinated by bees.
Other Names:
Greek Mustard, Shortpod Mustard, Silver Mustard.
Frequency (UK):
Occasionally seen  

Similar Species

Other Information


Hirschfeldia incana, also known as silver mustard, is an annual herb that is native to Mediterranean region and southern Europe. It is a member of the Brassicaceae family and can grow up to 2-3 feet tall. It has small, yellow flowers that bloom in the late spring and summer. The leaves are blue-green and covered in fine, silky, white or silver-colored hairs, which gives the plant a characteristic silver-gray appearance. Hirschfeldia incana is considered an invasive weed and it can be found in waste ground, roadsides, and along paths. It is tolerant of poor soil conditions and can be difficult to control. It is not commonly used in traditional medicine or as a culinary herb, but it's cultivated for forage and as a green manure crop.


Hoary Mustard, also known as Hirschfeldia incana, is a versatile and hardy plant that is native to the Mediterranean region but has spread to many parts of the world. It belongs to the family Brassicaceae, which includes other well-known plants such as broccoli, kale, and mustard greens.

The hoary mustard plant is an annual or biennial that can grow up to 3 feet tall. It has grey-green leaves that are hairy and can grow up to 6 inches long. The flowers of the hoary mustard are bright yellow and can appear from late spring to early fall. The plant produces long, thin seed pods that can be up to 2 inches long and contain numerous small seeds.

Hoary mustard is an invasive species in some parts of the world, including the United States, where it has become a problem in many areas. It is a fast-growing plant that can quickly colonize disturbed areas such as roadsides, agricultural fields, and waste areas. It can also outcompete native plants, reducing biodiversity in the ecosystem.

Despite its invasive tendencies, hoary mustard has some uses and benefits. The plant is edible, and the leaves, flowers, and seeds can all be consumed. The leaves have a mild mustard flavor and can be used in salads or cooked as a green vegetable. The seeds can be ground into a powder and used as a spice or made into a condiment similar to mustard. In some cultures, the plant is also used for medicinal purposes.

Hoary mustard is also a valuable source of nectar for bees and other pollinators, making it an important plant for maintaining healthy ecosystems. Its deep taproot can also help improve soil quality by breaking up compacted soil and increasing water retention.

Hoary mustard is a plant with both positive and negative qualities. While it can be invasive in certain areas, it also has value as a source of food and as a contributor to healthy ecosystems. As with any plant species, it is important to manage its spread and use it in a responsible and sustainable manner.

Hoary mustard has a long history of human use, dating back to ancient times. It is believed to have been used by the ancient Greeks and Romans as both a food and a medicine. In traditional Chinese medicine, the plant is used to treat coughs, fever, and other ailments.

In addition to its culinary and medicinal uses, hoary mustard has also been used for its oil. The seeds contain a high amount of oil, which can be extracted and used for various purposes such as cooking, lighting, and lubrication.

Despite its many uses, hoary mustard is still considered a problematic weed in many areas. Its fast growth and ability to spread quickly can make it difficult to control, especially in agricultural areas. Some methods of control include mechanical removal, herbicides, and biological control using insects or fungi.

However, it is important to note that hoary mustard is not the only invasive species causing problems in ecosystems around the world. Invasive species can have significant negative impacts on biodiversity, agriculture, and other aspects of the environment. It is important for individuals and communities to be aware of invasive species in their area and take steps to prevent their spread.

Hoary mustard is a highly adaptable plant that can grow in a variety of soil types and conditions, including nutrient-poor soils, and can tolerate both drought and flooding. This adaptability has made it a successful invader in many areas around the world, where it outcompetes native plants and disrupts local ecosystems.

One of the reasons why hoary mustard is so successful at invading new areas is due to its ability to produce a large number of seeds. The plant can produce up to 10,000 seeds per plant, which can remain viable in the soil for up to 10 years. This means that even if a plant is removed, there is still a high chance that new plants will grow from the seeds left in the soil.

Despite its invasive tendencies, hoary mustard has been found to have some positive ecological impacts in certain areas. For example, studies have shown that hoary mustard can be beneficial in restoring degraded soils, as it can improve soil structure and increase nutrient availability. It can also help to prevent soil erosion and reduce the impacts of heavy metal pollution in soil.

In terms of its culinary uses, hoary mustard has a mild, slightly bitter flavor that is similar to other mustard greens. It can be eaten raw in salads or cooked as a vegetable, and is often used in Mediterranean cuisine. The seeds of the plant can also be ground into a powder and used as a spice or condiment, similar to traditional mustard.

Research has also shown that hoary mustard may have potential as a biofuel crop. The plant contains high levels of oil, which can be extracted and converted into biodiesel. This could be a more sustainable and environmentally friendly alternative to fossil fuels, as it would reduce greenhouse gas emissions and dependence on non-renewable resources.

Hoary mustard also has a role in traditional and cultural practices in different parts of the world. For example, in Tunisia, the plant is used in traditional medicine to treat various ailments, including fever, diarrhea, and inflammation. In some regions of Italy, hoary mustard is used to make a traditional condiment called "mostarda di frutta," which is made by candying fruit in a syrup made from mustard seeds.

In addition to its cultural and traditional uses, hoary mustard has potential for use in ecological restoration projects. The plant's deep root system can help to break up compacted soils and increase soil organic matter, which can benefit native plant species. Additionally, the plant's ability to attract pollinators can help to support the health and diversity of local ecosystems.

Overall, hoary mustard is a plant with a complex and multifaceted relationship with humans and the environment. While it can be invasive in certain areas and cause problems for native plant species, it also has value as a source of food, medicine, oil, and as a contributor to healthy ecosystems. Further research is needed to fully understand the plant's potential uses and impacts, and to develop strategies for managing its spread in a sustainable manner.

Distribution Map

Reproduced by kind permission of the BSBI.

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