Hedge Garlic or Jack-by-the-hedge.


Garlic mustard, Alliaria petiolata is known by a number of country titles, such as, hedge garlic, sauce alone and probably the most commonly used jack-by-the-hedge. This species must not be mistaken with others of similar sounding names such as wild garlic and hedge mustard.

Although this herb is classed as a biennial it appears every year, where established, it is common in damp, shady places especially hedge bottoms. They tend to spread along hedgerows and along lanes in a linear fashion seldom spreading into fields, and it is all but absent on agricultural land.It is an invasive plant in as much as its dense rosettes of basal foliage does not allow other species to compete for room or light. On the other hand the seeds are an important source of food for many farmland birds including the brown linnet. It is also an important plant for certain butterflies and their larvae.  These include the large white, Pieris brassicae {the one that whose caterpillars eat your cabbage and nasturtium leaves} the orange tip Anthocharis cardamines, green veined white Pieris napi and the small white Pieris rapae.

The plant has a characteristic odour of garlic when bruised. The milk of cows that have grazed on the plant is often tainted.


Cows that graze on this plant may have tainted milk.

Dal.dalswildlifesite.comShould these grazing cows eat garlic mustard the milk could be tainted. Photograph D.A.L.

Basic biology

 It is an almost hairless plant that may attain the height of over a metre although locally 36 inches is a good size. The stems are erect and tend to have soft white hairs near the base. The characteristic heart-shaped leaves are long stalked as the plant grows. Those on the stem are in contrast short stalked and triangular in out line.


New growth of a single specimen.

Dal. dalswildlifesite.comI found this single specimen to photograph the heart shaped basal leaves.

Flowers and seeds

The flowers are white with four petals formed in the shape of a cross. { many plants of this family have petals that form a cross, collectively they are known as the crucifers}. beneath the petals the four sepals are green and 2.5-3mm long, they support the petals,{and protect them when in bud} The fruit {seed container} are some what elongated and pod shaped capsules known to botanists as siliqua. These are 3-6cm long. The actual seeds are dark brown almost black approximately 3mm long. The siliqua contains 10-20 seeds. Studies have shown that the seeds nearest the base of each individual siliqua are likely to achieve maturity. It also reveals that seedlings from smaller seeds often grow taller.

The seedlings emerge between January and April and gradually form a long tap root. Garlic mustard survives the winter as a rosette of leaves, it is likely that they perennate from adventitious buds on the roots. They establish rapidly from soil disturbance. Grooves along the seed coat trap air and enable the seed to float on water.

Jack-by-the-hedge or in this case a wall

Dal.dalswildlifesite.comjack-by-the -hedge , or in this case a wall.

Medicinal uses.

Culpeper the 17th century herbalist recommended the plant should be one of the main ingredients in herbal tonics

Active ingerdients--Mustard oil, glycosides,suphar-rich, essential oils, cardiac glycosides.

In archaic times it was used to treat bronchial diseases and worms. Although the plant is not so much used today it is sometimes used as a poultice to treat wounds and ulcers.

However, the culinary virtues are still utilised by country folk. The fresh young leaves may be added to salads. I have often used the leaves, cutup finely to make a sauce, in the manner of home made mint sauce. It makes a good alternative. The taste of garlic from this plant is not as strong as that of wild garlic foliage which I find to be a little over powering.

This is the only member of the cabbage family to taste and smell of garlic. All other plants that do so belong to the onion family. Liliaceae.

While out on a foray to take the pictures of garlic mustard, I came across two other species that were worthy of photographing. The common dandelion when in any numbers make an impressive display. Honesty with its purple, pink flowers brightens the hedgerow.

Honesty is another springtime flowering plant found in similar habitat

Dal.dalswildlifesite.comHonesty brightens the hedgerow and road sides. Photograph by D.A.L.

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