Even in a small garden, one of my favorite things to grow is yacon or Bolivian sunsroot. I've never seen it sold at farmers' markets or produce stands.
If you're a fan of crunchy foods, you might like yacon. It has a carrotlike taste, with earthiness and a hint of sweetness (which increases as it ages) and a little resinous note. But what really sets it apart is the texture. It's a brittle juicy crunchiness. If the crunchy scale goes from carrots to apples and bosc pears, yacon would be the next step on the scale, and watermelon would be at the end. It's not as hard and dense as a carrot, and it's juicier than the juiciest crunchy-hard bosc pear, but not a dripping type of juicy, and not as juicy as watermelon. Can't think of anything like it.
Last winter as I was eating it, I thought of yacon as winter white watermelon.
In the garden, it's easy to grow. Yacon needs regular water, rich soil, part to full sun, and a 6-8 month growing season. It's frost tender, so the rhizomes start sprouting in April but are sometimes set back by late frosts. By late summer to early fall it's up to 7 ft. high and wide (smaller with less water or poorer soil) with large, soft leaves.
I like to plant yacon where it can shade other plants in the heat of summer, but it can also grow among other tall sun-loving plants. One year I let a volunteer squash plant twine through it, and another year it was in the middle of the tomato bed. Where I've planted it in the shade, it's gotten only a couple feet high.
Small daisylike flowers emerge in late fall, just before the first frost in early December blackens the leaves. I cut back the stems, leaving a few inches so I can find the edible parts later.
I usually get around to harvesting the edible storage roots in mid-January, when I have a break from other garden tasks. For a big, healthy plant, I often have to dig down a foot or so to find all the storage roots, typically several pound-plus roots per plant. You're supposed to be able to harvest as needed, but I find when I start digging, pieces break off and I end up harvesting the whole plant at once. Between the stem and the storage roots are a mass of rhizomes, which I save to grow new crops. I always have plenty of rhizomes to divide and give away.
Yacon stores well. This year, I harvested enough to last through mid-March. It's not a good idea to eat a lot at once, because yacon contains inulin, which produces gas.
Inulin is reputed to be good for the soil life, so when I have any extra space in the garden, even if it's late in the season, I plant a yacon plant there to help build soil. Yacon will survive in containers, but it won't get big and won't produce many storage roots.
© 2010 Tanya Kucak