The Canadian Truffle, Sunchoke, Sunroot, or Jerusalem Artichoke (Helianthus tuberosus) is a very interesting example of a semi-domesticated crop that formed part of the land management practices of certain Native American peoples.
They would plant the roots in areas near seasonal camps, and let the plants grow without care, as part of the landscape, until needed. This could be a season or ten seasons later.
Needless to say, this practice promoted the spread of this long lived, perennial relative of the common sunflower throughout North and Central America.
The plant is extremely attractive both to humans and bees, and grows as a tall (2m+) cluster of stems topped with hundreds of small, yellow sunflowers throughout summer.
The ‘Jerusalem’ part of one of the plant’s common names is a corruption of the Italian ‘girasole’, another name for sunflower.
The edible parts of the crop include its flower petals, but the real harvest lies underground, because at the end of the growing season the plant will die back, leaving vast quantities of ginger-like roots below ground. These are ready for harvest, which one can do as one needs them all winter long.
These roots are edible raw or cooked, with a crunchy texture when raw, and are great in a salad.
When roasted or boiled they have a delicious, sweet artichoke flavour with a tinge of sunflower seed that is quite distinctive. They will quickly become your favourite winter vegetable!
The roots have a small amount of protein and virtually no starch but are rich in the carbohydrate inulin, which is a polymer of the monosaccharide fructose. Good news for those watching their sugar intake. Inulin is not assimilated by the intestine, making it a dietary fibre and prebiotic, digested by the intestinal microflora, so does not cause a glycaemic spike.
Low glycaemic index
To explain further, this a low GI “starchy” vegetable, and considered moderately ketogenic. More importantly, research using mice has shown inulin may alleviate diabetes and increase beneficial intestinal microbiota.
In other words, this crop may may be useful as a functional food in the prevention and/or treatment of hyperglycaemia.
Dormant tubers convert their inulin into small quantities of the structural component fructose, increasing the root’s sweetness.
First winter cold spell
In fact, it is best to only start harvesting your sunchokes after the first winter cold, as this process starts in earnest then.
A word of warning: the process of inulin digestion by the intestinal microbiome can cause flatulence in some people, leading to the plant’s other common name “fartichokes”.
Generally speaking the effect becomes much less once the internal microflora adapt to the inulin intake.
League of its own
This plant is productive enough to literally be in a league of its own, outperforming any root vegetable you may have grown, but is a long season grower. Tubers can be planted from mid-winter to very early spring and the harvest is ready once the plants die down for winter. Therefore plant this in an area of your veggie garden where it can grow undisturbed.
It is best to leave the tubers in the ground, digging them up as necessary for the kitchen, as they store best in cold soil.
There will always be enough left in place to start the sunchoke patch up again in spring.
In fact advice to heed when planting sunchokes is to plant them in an area of the garden where you never want to grow anything else ever again!
Early spring sprouting
Sprouting of the tubers takes place without any warning in very early spring, so they are best planted before the end of the winter cold.
Prune for bigger tubers
If you live in an area with frosts, plant while these are still occurring most nights. One can get much bigger tubers if one allows the plant to grow to blooming size, then cut it down by half. Control any attempts to flower thereafter by removing buds so that all the plant’s reserves go into producing roots.
But, honestly, the yield on a stand of sunchokes is so big there really is no need, and one can enjoy the flowers and the pollinators they bring.
Plants can spread aggressively in moist soil but are easily contained with bamboo barrier, bidem/weed guard or a raised planter as the roots are shallow.
This crop prefers full sun, but will tolerate broken shade, dies down in winter and, as mentioned, cold and frost cause the tubers to sweeten.
Hardy and pest free
Plants are extremely hardy, and virtually pest free. In fact, one can use the liquid from chopped, boiled leaves and stems on other plants to repel aphids as an environmentally friendly, non-toxic remedy.
Sunchokes must have consistent moisture during the growing season. This is very important, and one can lose an entire colony of this species if it is subjected to prolonged or repeated drought.
Despite its exotic origins, this is a non-invasive plant and does not produce seed despite its copious flowers. It can only grow where it is transported to, and planted by man, due to cytoplasmic pollen sterility in domesticated cultivars.
Roots can be traded when dormant in winter, or plants purchased in bags from selected nurseries in summer.
Tubers should not be stored out of the ground for long as they desiccate easily, but will stay fresh in moist soil for a very long time.
Tubers are fantastic in stews and potjies, mashed on their own or liquidized in a soup. They have a distinctive flavour that one can pick up on in any recipe.
One of the best recipes for a meat eater is to cook a pork or mutton rib over a bed of sunchokes. The oils and juices from the cooking meat permeate and caramelize the tubers. A treat fit for royalty!
For more information contact Jason Sampson at firstname.lastname@example.org
All images: Hay’s Harvest