Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..

I am finding Garlic Mustard everywhere at the moment – in the cemetery, along the edge of the allotments, everywhere that is damp and shady. I also found it in the hedgerows of Somerset, where it seems very at home, peeking out from a mass of bluebells, nettles and stitchwort, and living up to its alternative name of Jack-by-the-hedge.  Its leaves are a most toothsome shade of pale green, and smell slightly of garlic when crushed. The four-petalled flowers are in a cross or  ‘cruciform’ shape (hence ‘crucifers’): this is an indicator that we are dealing with a member of the Brassica, or cabbage family. Many of this family share Garlic Mustard’s pungency: some have that familiar school-dinners sulphur smell when squashed or cooked, and other have the stronger notes of mustard or horseradish. Human beings appear to have been using Garlic Mustard to spice their food for a very long time: seeds of the plant were found in pots that are over 6000 years old, along with mammal and fish remains, suggesting that some kind of stew had been made with Garlic Mustard as a flavouring. The plant has much higher Vitamin A and Vitamin C levels than most commercially-grown fruit and vegetables (8,600 units/100g and 190 mcg/100g respectively), and so would have been an excellent choice as a pot-herb or flavouring.

The mustard flavour is not there for our benefit, of course. Deer seem to dislike the taste, and so it goes largely unforaged. However, the scent attracts the midges and hoverflies that are its main pollinators. It is also the foodplant of the Orange-tip Butterfly caterpillar, and the long green larvae particularly like the seed pods of the plant. The caterpillars  seem to be perfectly matched, in shape and colour,  to the seedpods, which are their favourite part of the plant.

I saw my first Orange-tip butterflies today, jousting above a patch of Garlic Mustard. I shall have to go back later to see if I can see any eggs. They are the colour of barley-sugar, as elegant as the butterfly that made them.

In the UK, Garlic Mustard is part of a mix of woodland flora, and behaves like a responsible part of the plant community. In eastern North America, however, it has become something of a problem plant. In the UK, 69 species of insect feed on the plant, but across the Atlantic nothing does. Occasionally, butterflies that are related to our Orange-tip lay their eggs on the plant, because it looks similar to native crucifers, but the larvae sicken and die. Deer mostly disdain Garlic Mustard, as they do here. Furthermore, the plant seems to produce chemicals which inhibit the growth of other plants. This chemical warfare doesn’t happen in the plant’s natural range, possibly because defences have evolved to keep everything in balance. However, I note that Garlic Mustard was first imported to America as a food plant in 1800, and wonder whether it has always been a problem, or if something else has changed which has made it more vigorous than it was previously? As always, these things are not simple.

However, it’s fair to say that the plant is being given a run for its money. There are Garlic Mustard Pulling competitions, where different areas compete to see how much of the plant they can eradicate. There are many recipes online for tasty ways to use Garlic Mustard once you’ve pulled it up: here is a Garlic Mustard Roulade  and here we have some Garlic Mustard Hummous. Both of these sound rather good, and would be fun if you have a superabundance of the plant. More drastic measures include the application of herbicides such as glyphosate, and even use of controlled fires.  But I suspect that, in the end, the plant and its environment will come to some kind of accommodation, even if the timescale is one that humans will find it rather difficult to live with. Having taken a living thing from its normal habitat for our own purposes, we are now left with the consequences of our actions. Let’s hope that the remedy doesn’t prove worst than the disease.