Summer cereals at Kew
Kew's Grass Garden has a comprehensive display of cereals from around the world - grains such as wheat, barley, sorghum and millet - and now is the best time to come and see them.
Like many botanic gardens, Kew has long had a tradition of a specialist cereals bed. Just three cereals, wheat, rice and maize provide 60% of the world's food energy, so it is an important story to tell. Today the cereal bed is located in the Grass Garden, behind Hamo Thornycroft's statue of The Sower. As part of the IncrEdibles Festival, the display has been refreshed and new interpretation boards erected.
The cereal beds in Kew's Grass Garden (Photo: Mark Nesbitt)
What is a cereal?
It's the term for grasses that bear edible grains. These are so important because the cereal grain is the ideal food package, with starch wrapped in bran and husks, giving good protection from storage pests. As the grains are dry they keep well and are easy to transport. Although humans find it hard to digest raw starch it can easily be turned into a food by cooking or malting. It's not surprising that the development of ancient civilisations around the world is usually closely linked to the development of cereal cultivation.
The challenge of displaying cereals
The cereal beds are a special challenge for my colleague Michelle Cleave, who looks after the Grass Garden. To maintain such a comprehensive display (dare I say the fullest of any botanic garden?) seeds have to be collected all year round. Cereals hybridise easily, so there is a limit to how long seeds can be saved and replanted. The cereals can look very similar, especially when young, so very careful attention must be given to labels when planting out.
If the Spring is dry the cereals don't thrive; if (as this year) it is wet, the cereals grow too tall and fall over. This is not helped by visits from birds and badgers. Most botanic gardens enclose their cereals in a netted cage, but some people find this unattractive in a garden context. Nonetheless, we persevere!
Perhaps the greatest challenge in presenting cereals is how to capture such a variety of rich and fascinating stories without a forest of information panels. Museums are using touchscreens and one day we might see these in outdoor environments. For the time being, I'll just highlight some cereals to look for.
Part of the wheat display, showing one of the new interpretation panels (Photo: Mark Nesbitt)
Cereals' wild ancestors
Wherever possible we show the wild ancestor of the cereal next to the cultivated, domesticated form. Some of the differences between wild and cultivated forms are hard to see in our cereal beds: for example, the cultivated forms usually have larger grains. But one difference is easy to see in wheat and barley. In the wild forms, the cereal ear breaks up as it ripens, scattering the packets of grain onto the ground. While that is good for seed dispersal in the wild, it is not so ideal for the farmer. So in cultivated forms, the ear stays intact through to harvest. The image below shows wild einkorn wheat on the right, and you can see the ear is no longer complete.
Knowing about the wild ancestor is important to archaeologists who want to understand the processes by which agriculture first developed. It is also vital for the plant breeder as wild relatives are often a source of genes for characters such as disease resistance and adaptation to climate change. My colleagues at the Millennium Seed Bank are currently working on the Crop Wild Relatives Project, identifying parts of the world where wild relatives have not yet been sufficiently collected.
Einkorn wheat (Triticum monococcum). Domesticated form on the left, wild on the right (Photo: Mark Nesbitt)
As well as the major commercial wheats, bread wheat (Triticum aestivum) and macaroni wheat (T. durum), we showcase many obscure wheats that were once locally important. Some of these are seeing revived cultivation owing to the interest in traditional foods: for example farro (T. dicoccum) in Italy, and spelt wheat (T. spelta) in many countries including the United Kingdom. While not suitable for making modern highly processed breads, they offer a far tastier alternative, whether as bread, pasta or porridge.
Miracle wheat, shown below, has attracted much interest over the years. It is a form of rivet wheat (T. turgidum) with branched ears. It is also known as mummy wheat, although it has nothing to do with ancient Egyptian farmers (who only grew emmer wheat). Although miracle wheat looks amazingly prolific, sadly its yield by area is less than that of unbranched wheats. Normal rivet wheat is increasingly cultivated in Britain (after virtually disappearing) because its long straw makes it suitable for thatching. Modern wheats are bred to have short stems so they do not fall over when given heavy inputs of fertiliser.
As well as the wheats, the temperate cereal bed contains barley, oats and rye.
Miracle wheat (Triticum turgidum var. pseudocervinum)
Tropical cereals on the way
By the end of July, the temperate cereals will be in poor condition and attention will switch to the tropical cereals in the bed behind. These will look good until October. These cereals originate in Africa and Asia; we can no longer grow maize owing to animal damage and rice is grown inside the Water Lily House.
The tropical cereals bed, with sorghum plants at this end.
The tropical cereals, such as sorghum and the many different millets, are important because they grow well on poor soils and dry climates. While the amounts cultivated are small compared to wheat, maize and rice, they play a vitally important role in areas not reached by the Green Revolution that has hugely increased cereal yields in more accessible places.
- Mark -
- Find out more about cereals at Kew's IncrEdibles Festival
- "Les meilleurs blés" (The best wheats) - a beautiful illustrated guide from 1880
- Wheat - the Big Picture