Smallanthus sonchifolius (previously Polymnia sonchifolia and P. edulis)
This is one of those edibles that you won’t find in the supermarket. Which is fine as it grows so easily and abundantly here. What is it? Also known as Peruvian ground apple. It’s crispy and very juicy like a cucumber and slightly sweet like a pear. It’s a chunky vegetable or fruit. Imagine a large tuber about the size and shape of a sweet potato. With an ugly thin brown layer of skin that needs to be peeled off! All white inside which will need a squeeze of lemon or lime juice once cut otherwise it turns brown. The sweet taste does not tend to come from sugar but mostly from fructooligosaccharides (FOS), large sugar molecules that are mostly undigestible by humans, so it’s great for diabetics to enjoy. (1)
Yacon is very versatile in that you can bandicoot for the storage tubers any time of year for a juicy, thirst quenching (though probably not that sweet) snack on a hot day. (1) You can enjoy as a sweet fruit once mature. They go well in salads. They add zing to any juice, though are really bland on their own. (2)You can cook them up as a vegetable and use anywhere you would use water chestnuts – they keep their crunch when cooked. They can be used in fruit crumble. (3) They can be boiled in their skin which peels away when cooked. (3) They are recommended roasted. (2) You can dehydrate them and enjoy sweet chips. (4) Or boil down to a sweet diabetic-friendly syrup. (5) The main stem can also be used like celery. (2)
This is a member of the sunflower family. It’s prolific and not a fussy or difficult plant. Yacon is grown successfully in all sorts of climates, from northern Canada to Hawaii. It originates from the Andes, on the eastern sides of the mountains with more humidity and heat than the west. (1) Funnily enough, though yacon is not fussed about climate, what it really likes is…. altitude. 1500 – 2000m of height above sea level is where it is most productive. (6) So that’s actually more like Dorrigo or higher! Never mind, it grows just fine here. Though it grows better up the escarpment.
Before we get into the planting and growing detail, a little anatomy lesson. Yacon is a little unusual in that the bit we eat is known as the storage tuber. This is separate from the rhizome which grows new plants. The rhizome is a smaller red tuber that sits above the large brown storage tubers, underground, ready to send up stalk shoots next spring. (1)
So, you eat the brown tubers. These will not grow into plants.
You separate and plant the small red tubers. These have small knobs ready to shoot into new plants.
Ideally you plant in spring. (1) About August / September but it’s not fussy and will grow happily as long as there is no chance of frost. Yacon absolutely hates frost. (1) Choose a spot that is suitable for a plant that will grow 1 – 3 m high. (5) Wind will knock it over as it’s so tall and relatively weak stemmed. It needs to have shelter from anything other than a breeze. (1)
Bury rhizomes 10cm deep and 60 – 80 cm apart. Yacon is not fussy about soil. It is a heavy user of potassium and appreciates this added, in addition to some compost which should take care of it’s modest feeding requirements. Yacon is slow to grow until the weather really warms up. (1) It does not like competition from weeds while it is getting established. Mulch around it to keep them under control. (7) Yacon is mostly water. It will do best with watering, (1,6) though it absolutely does not like wet feet ie no waterlogged soil. (8)
It has to be said, this is a bit of a plant and forget kind of plant. You will still probably end up with a harvest if you neglect it.
At any time once the plant is established, you can bandicoot for a storage tuber or three to munch on. What’s bandicooting? Carefully tunneling under the plant to harvest only what you need right now, without digging the whole plant up. Leave it as undisturbed as possible to continue growing. Tubers harvested early are unlikely to be sweet. They should be full of watery crispness, but more cucumber than watermelon.
There is a myth that harvesting is best done just after flowering. While you can harvest any time, research has shown that the last couple of months of growth (after flowering) adds significantly to the amount of edible tubers you end up with. (9)
The tubers are at their harvesting best once the green foliage has COMPLETELY died off. The sugars in the aerial parts are driven down down down into the storage tubers as the foliage dies. (10) Here, this is around July, near the end of winter. Dig them all up and separate the edible storage tubers from the crown of rhizomes for replanting. It’s recommended to leave some small storage tubers attached to the planting rhizomes. This is where they get their energy for growing. (1)
Harvesting is always a bit messy. It’s impossible no matter how careful you are to not break or bruise tubers. Be careful but know that this is inevitable. Use these broken ones first as they don’t store.
There is a little bit of debate about sweetening and storage here. It is known that some of the indigestible sweetness is converted into sugar which improves the flavour after the yacon is harvested. The recommendation is to let the tubers lie in the sun for a week or in a cool dark place for 4 weeks for maximum sweetness. (1) The local experience is that a few days in our sun is enough to start the tubers turning mushy (rotting). (11) A number of local growers have found it’s sweet enough if you let the foliage die down with no need to wait for it to sweeten up, (4,8,11) though waiting a few weeks does improve them. (8) Yacon is meant to store for many months in similar conditions to potato storage ie cool (10°C), dark place with airflow, plus a bit of humidity. (1) My experience is maybe a few months, not many months.
Note, yacon does not freeze well. It turns to mush. (10) It does however, keep for months in the fridge. Even in a plastic container, all peeled, chopped up and with a squeeze of lemon juice ready to go. (4)
A quick run down of a couple of related and useful plants.
Jeruselum artichokes / Fartichokes
Also in the sunflower family.
A fabulous food resilience crop, hardy and prolific with a lovely nutty flavour, IF you aren’t affected by their renowned gas-inducing tendencies. Many people are, and the amount of stomach upset, bloating and pain can be significant. Take it from me, don’t be tempted to make a hearty bean and fartichoke soup. The results can be terrifying! Some lucky people aren’t affected and can fully enjoy these like potatoes or parsnips. Some strains or varieties of fartichoke are far worse than others for causing gassiness. If you find a mild strain, please do us all a favour and grow as much as possible and spread those tubers around to everyone to grow.
This is another tall plant with a small sunflower-like flower, which dies down in autumn / winter. It creates about 12 new tubers per plant. (12) The flavour is best after frost. They can be eaten raw or cooked! (13) And like yacon, this needs a squeeze of lemon juice once peeled or cut to prevent browning. (14)
The details of growing and harvesting fartichoke are very similar to yacon. With this plant though there is only one tuber for growing and eating. Save your best tubers and replant. Try and choose the least knobbly ones. Over generations you will end up with a strain that is smoother and easier to peel.
Sunflowers for seed or oil
The namesake of the sunflower family is not just a rather stunning flower. The seeds are a good source of protein and the oil pressed from the seeds is one of the world’s most popular. (15) Though you may find yourself growing a crop of king parrots instead. (16)
In a home garden situation, the flowers are ready to harvest for seed once the backs of the flowers begin to yellow. (17) In my experience, the birds are into them way before this. You will need to make the effort to cover each flower with something to stop the birds feasting on all the seeds. Mesh bags or cheesecloth are two of the more sensible solutions I’ve heard of. (18,19) Mere paper bags do not fool the birds around here for very long.
One giant sunflower head will give you approximately 4 cups of unhulled sunflower seeds. (20) These can be soaked overnight in plain or salty water, then roasted and flavoured and you have a ‘split and spit’ snack. (21) The hulled sunflower seeds we are familiar with in baking are mechanically hulled, and if you want to use them like this, you’ll need to take the time to roll them gently in a mortar and pestle (22) or with a rolling pin (23) to loosen the shell, half a cup at a time. Tipping the results into a bowl of water will separate the seeds which sink from the hull which floats. (23) Seeds also make good microgreens / sprouts and don’t need to be hulled for this. (19,24) And you can snack on the seeds raw, as a slow food split, nibble, spit arrangement. Commercially, grey striped kernels are usually larger and used for food, while black kernels have twice as much oil and so are pressed. (17)
Seeds average 51% oil (15), so with a back of the envelope calculation, one giant sunflower head would yield around 2 cups of oil. A modified car jack works as a press. (17) These are some plans: http://journeytoforever.org/biofuel_library/oilpress.html The leftover seed cake is high in protein.
Again, growing conditions are quite similar to yacon and fartichoke. Plant sunflowers in spring and keep the water up to them while flowering.
Big thanks to all the local growers who responded to my call for contributions. In no particular order: Pete Bufo, Tim Hill, Evelyn Wilke, Georgie Moon, Lesley Green, Nicola Fraser Pat Wheeldon, Adrian Betts, Linda Bizon, Don Cooper, Kris Heather, Shaun Robinson, Charles Filet
Supported by Bellingen Shire Council via the Bellingen Shire Disaster Recovery and Resilience Grant Program Funding
1. Growing Yacon [Internet]. Cultivariable. [cited 2021 Jul 6]. Available from: https://www.cultivariable.com/instructions/andean-roots-tubers/how-to-grow-yacon/
2. Posted by Lissa on June 4 2011 at 6:00, Blog V. YACON/YAKON [Internet]. Brisbane local food. [cited 2021 Jul 6]. Available from: https://brisbanelocalfood.ning.com/profiles/blogs/yaconyakon-1
3. Yacon – Peruvian Ground Apple growing information [Internet]. Green Harvest. [cited 2021 Jul 6]. Available from: https://greenharvest.com.au/Plants/Information/Yacon.html
4. In a reply from Adrian Betts to my post on yacon, jeruselum artichokes and sunflowers in Bellingen Seed Savers Chatter on July 6 2021 and in conversation on July 9 2021.
5. Manrique I, Parraga A, Hermann M, International Potato Center. Yacon syrup: principles and processing. Lima, Peru: Centro Internacional de la Papa; 2005.
6. Silva DMN da, Oliveira FL de, Cavatte PC, Quaresma MAL, Christo BF. Growth and development of yacon in different periods of planting and growing regions. Acta Sci, Agron [Internet]. 2018 Sep 3 [cited 2021 Jul 6];40. Available from: http://www.scielo.br/j/asagr/a/4rdrZhwpsZ7zy4LDCMC4BXk/?lang=en
7. Cabral MO, Oliveira FL, Dalvi LP, Teixeira AG, Rocha LJFN, Pedrosa JLF. Influence of Weeds on Yacon Initial Growth and Development. Planta daninha. 2020 Jan 15;38.
8. In a reply from Evelyn Wilke to my post on yacon, jeruselum artichokes and sunflowers in BOGG Facebook group on July 6 2021.
9. 2002_7._Fructo-oligosaccharide_prod_in_yacon.pdf [Internet]. [cited 2021 Jul 6]. Available from: https://www.agronomysociety.org.nz/files/2002_7._Fructo-oligosaccharide_prod_in_yacon.pdf
10. In conversation with Shaun Robinson on 10 July 2021.
11. In a reply from Georgie Moon to my post on yacon, jeruselum artichokes and sunflowers in BOGG Facebook group on July 6 2021.
12. JERUSALEM ARTICHOKE | The Diggers Club [Internet]. The Diggers Club. [cited 2021 Jul 12]. Available from: https://www.diggers.com.au/shop/warm-soil-vegetables/jerusalem-artichoke/bjea/
13. Buy Jerusalem Artichoke plant- Helianthus tuberosus [Internet]. Daleys Fruit. [cited 2021 Jul 12]. Available from: https://www.daleysfruit.com.au/Perennialveg/jerusalem.htm
14. Jerusalem Artichokes | Exotic Fruit Traders [Internet]. Exotic Fruit Traders. [cited 2021 Jul 12]. Available from: https://www.exotic.com.au/?product=jerusalem-artichokes
15. Sunflower seed. In: Wikipedia [Internet]. 2021 [cited 2021 Jul 12]. Available from: https://en.wikipedia.org/w/index.php?title=Sunflower_seed&oldid=1028610006
16. In a reply from Nicola Fraser to my post on yacon, jeruselum artichokes and sunflowers in Bellingen Seed Savers Chatter on July 6 2021.
17. Coleby-Williams J. Super sunflowers [Internet]. Organic Gardener Magazine Australia. 2009 [cited 2021 Jul 12]. Available from: https://www.organicgardener.com.au/blogs/super-sunflowers
18. Editors T. The Right Way to Grow Gorgeous Sunflowers [Internet]. Good Housekeeping. 2020 [cited 2021 Jul 12]. Available from: https://www.goodhousekeeping.com/home/gardening/a20706857/how-to-grow-sunflowers/
19. In conversation with Charles Filet on 12 July 2021.
20. Mahaney E. Growing and Roasting Sunflower Seeds [Internet]. Under the Solano Sun – Seasonal observations of the UCCE Master Gardeners | ANR Blogs. 2018 [cited 2021 Jul 12]. Available from: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=28650
21. Shepard A. How To Harvest Sunflower Seeds For Planting, Roasting, and Feeding Birds | American Meadows [Internet]. [cited 2021 Jul 12]. Available from: https://www.americanmeadows.com/blog/2016/10/12/harvest-sunflower-seeds-planting-roasting-feeding-birds
22. Onyx Food Hill. Sunflower seeds: How to peel the shell Sunflower seeds easily- Sunflower seeds shell removal at Home [Internet]. [cited 2021 Jul 12]. Available from: https://www.youtube.com/watch?v=nwRL5guCq6g&t=123s
23. Hessong A. Easy Way to Shell Sunflower Seeds [Internet]. LEAFtv. [cited 2021 Jul 12]. Available from: https://www.leaf.tv/articles/easy-way-to-shell-sunflower-seeds/
24. In a reply from Don Cooper to my post on yacon, jeruselum artichokes and sunflowers in Bellingen Seed Savers Chatter on July 6 2021.
25. Serafin L, Belfield S. Sunflower production guidelines for the Northern grains region Northern NSW Southern QLD. NSW Department of Primary Industries. 2008;8.
26. Roe A. GROWING SUNFLOWER – MANAGEMENT PACKAGE FOR DRYLAND WA. Australian Oil Seeds. :4.