What stops us from processing weeds into tasty and edible food?
Faith Anstey
Dalguise, Perth and Kinross, UK
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Because then they wouldn鈥檛 be weeds any more 鈥� they would be vegetables. As Ralph Waldo Emerson said: 鈥淲hat is a weed? A plant whose virtues have not yet been discovered.鈥�
Bryn Glover
Kirkby Malzeard, North Yorkshire, UK
Just about every plant cultivated for human consumption began life as a 鈥渨eed鈥�.
As someone who often forages for wild morsels, my experience is that few are worth the effort. Most are tough, stringy or bitter, and given the relative ease with which anyone can grow simple salad vegetables, the effort involved in foraging is rarely worthwhile. There are a few exceptions, such as young dandelion leaves or hawthorn leaves.
Richard Swifte
Darmstadt, Germany
Nothing stops us eating weeds other than commercial considerations. In fact, humans have been doing this for thousands of years, ever since we developed farming. 鈥淲eed鈥� is simply the word we use for plants that we don鈥檛 want in our gardens or agricultural fields.
Early hunter-gatherer humans, as well as our primate ancestors, ate suitable (i.e. tasty and non-poisonous) fruit, leaves and roots taken directly from nature. Farming then enabled us to start selectively breeding such plants to increase their edible output, so today we have a range of food plants that often appear very different from their wild ancestors.
There is, however, a niche market for a variety of wild plants. One is the dandelion, normally considered a weed. But this plant is edible and nutritious: dandelion leaves can be used in salad; its flowers are edible and can be used to make wine; and the roots can be roasted for a coffee substitute.
If, in the future, dandelion consumption were to become much more popular, then I see no reason why commercial breeding to produce larger leaves and bulkier roots shouldn鈥檛 occur.
Pat French
Rockhurst, Shropshire, UK
For the most part, if we haven鈥檛 cultivated a plant for food, there is probably a good reason.
If I take a sample of plants from a wild patch of my garden, there is a lot of grass, which we can鈥檛 digest; a bit of ragwort, which is toxic; and some yarrow, which is safe enough in small doses. Nettle and white mustard can be eaten and contain useful minerals, but aren鈥檛 very nutritious.
Many plants may be edible in that they (apparently) don鈥檛 harm us, but they may not necessarily feed us. We have exploited the most nutritious plants from their wild ancestors. Perhaps we can do the same with others if there is sufficient need.
[Ed. Before foraging for 鈥渨eeds鈥�, be aware than many can be toxic, and nettles need to be cooked to remove the sting.]
Charles Merfield
Lincoln, New Zealand
I have just published a paper on this very topic called . In it, I argue that the term 鈥渨eeds鈥� is a value judgement and that there is no scientific means for determining if a plant is a weed.
I use the example of Sonchus oleraceus: M膩ori people in New Zealand call this 辫奴丑腻 and consider it a nutritious and tasty vegetable, but 辫腻办别丑腻 [the M膩ori term for New Zealanders of European descent] farmers call it sow thistle and consider it a weed.
So, at one level, the only thing stopping us eating 鈥渨eeds鈥� is our value judgements of them. At another level, many plants that are commonly called weeds 鈥� for example, chickweed (Stellaria media) and fat hen (Chenopodium album) 鈥� used to be eaten. In the case of fat hen, it fell out of favour when spinach was introduced to Europe. At the same time, a number of weeds are unpalatable or toxic, so you have to know your weeds before you eat any!
Another issue is ease of production. With deep irony for weed scientists, many weed seeds are notoriously difficult to reliably germinate due to dormancy, despite them germinating like, well, weeds in cultivated fields. All crops have had this dormancy bred out of them, so will germinate as soon as they are sown. Also, many weeds don鈥檛 actually yield that much biomass compared with crops, so trying to grow them as a crop is uneconomical.
Finally, my proposed definition of weeds has the value judgement that weeds are 鈥減lants causing significant harm鈥�. So if a plant is being eaten, it isn鈥檛 a weed, it is food. This definition makes the concept of edible weeds a contradiction. I therefore introduced the term aliae plantae to define all the plants that are neither crops nor 鈥渞eal weeds鈥�.
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