Native to Europe, Asia and northern parts of Africa, wild mustard (Sinapis arvensis), also known as field mustard or charlock, is one of the tastiest and most versatile weeds in the brassica family.
The whole plant of wild mustard is edible and its botanical name, Sinapis, comes from the Greek word ‘sinapi’ meaning mustard. As well as making it easy to spot, its bright-yellow flowers make it a great pollen crop for bees and other important pollinator insects.
How To Identify It
Wild mustard is found right throughout the year, but is at its most abundant in spring and summer when its vivid yellow flowers are tall and on show.
It favours a heavier red clay soil over light soil and is often found on roadsides and along creeks where there’s plenty of water. A member of the brassica family, this delicious weed is distinguished by its leaves, which are large and lobed with frilled edges at the base of the plant, but which elongate into narrower leaves towards the top of the stem as the flower spikes grow.
Where other wild brassicas will have a pale lemoncoloured flower, wild mustard’s broccoli-like flower buds are followed by bright yellow flowers. The flowers are between 12 and 20 millimetres in diameter with four distinct petals surrounding six stamen, four long and two shorter, and they have a sweet aroma.
The seed pod – or silique – forms after the flower, with the seeds attaching either side of a thin, translucent membrane within the pod known as the replum. The ripe seeds have a mild mustard flavour which can also be used in cooking or to make a jar of wholegrain mustard (see breakout).
How To Use It
The young leaves are delicious eaten fresh in salads, while the older leaves have a stronger, almost bitter flavour and a texture which is better suited to being cooked before eating. Don’t forget about the mild, sweet flowers that can be added to salads, or the dried seeds which are a milder alternative to store-bought mustard seeds.
Historically, wild mustard has also been used medicinally as a mustard plaster or poultice. Said to have anti-inflammatory and wound-healing properties, it has been applied to sore joints or other areas of swelling, bruising and pain. It can be used as a natural decongestant and can also help reduce headache pain when steeped and consumed as a tea.
Other less-common uses for wild mustard are as a semi-permanent light-green dye, while its oil content makes it an effective fire starter. It’s important to note that once seed pods have formed, wild mustard can be poisonous to livestock.
Wild wholegrain mustard
1/3 cup apple-scrap vinegar
1/3 cup wild mustard seeds, or half yellow mustard seeds and half wild mustard seeds
1 tbsp olive oil
1/2 tsp horseradish
1 tsp salt
1 tsp water
In a glass jar, add the vinegar to the mustard seeds and allow to sit overnight. The following morning, blend two-thirds of the mix into a mustard-like consistency. Add the remaining seeds as well as the olive oil, horseradish and salt, and pulse to combine. Add the water only to reach the desired consistency. The mustard will store for up to two months in a sealed glass jar in the fridge.