December 2008
The Master Gardeners have just completed a trial of Andean root crops at their demonstration garden at the Elkus Youth Ranch south of Half Moon Bay. One of the crops chosen was Yacón (Polymnia sonchifolia). A distant relative of the sunflower, Yacón seems to thrive just about anywhere with consistent moisture and moderate sun and reasonable soil fertility. Rather than grow from seed, Yacón plants come from dividing the “crown, ”a ginger-like root structure where the edible tubers emanate. This is done, as with potatoes, with each new sprout emerging from an eye.
The plants can reach 5-7 feet tall, are quite attractive, and will only flower with a growing season of six months or more. We planted three little plants at the end of March. In mid-December, we harvested one plant which gave us a yield of 22 pounds of edible Yacón . We found this plant easy to grow with minimal pest problems. Although we grew our plants in zone 17, they should work equally as well in all of the climate zones in the Bay Area. It is believed that Yacón originated from the high Andean Region now known as eastern Bolivia and southern Peru. It is only recently, thanks to the efforts of a few intrepid plant people, that this unique cultivar is finding its way into the fields of North America. After a failed attempt at industrial scale cultivation and commercialization in Southern Europe in the 1930s, Yacón is now emerging as a commercial crop in South American, New Zealand, Japan and Korea. Here is a step by step description of how we grew our Yacón.
Our Yacón after a few weeks of being planted.
March 22, 2008: We purchased three plants from Nichols Garden Nursery in Oregon and planted them in native soil mixed with barn manure. No other fertilizer was used. Since these plants can grow tall, we built a trellis-type support behind them. They were planted at the end of our rectangular beds.
May 13, 2008: The Yacón are growing very slowly. We believe this to be our fault since we repaired the automatic drip irrigation system but forgot to turn it on. We also discovered some fungus on the leaves of one plant. The distributor sent us a replacement plant.
May 20, 2008: Transplanted the new Yacón plant.
July 15, 2008: Yacón is growing nicely. It is a beautiful plant with big hairy leaves and is being supported by the trellis with the help of some string.
Check out those yellow flowers.
December 13, 2008: The Yacón has continued to grow through the summer and fall. It has produced little yellow flowers and is growing very tall (over six feet). It is really a very attractive plant. It has finished flowering and the leaves are turning slightly brown. It is time to harvest but it is raining right now. We’ll harvest after the rains.
The Yacón has grown to about 6 feet.
December 17, 2008: Generally, one would harvest the plants after the first hard frost. However, At Elkus Ranch, we don’t have frost! We harvested one plant only. We first cut off the stalks. Then we started digging gently around the plant with our hands (sort of like digging up potatoes) in order to no break the tubers. The tubers are very delicate. After some time, we could lift the entire root mass out of the soil. We were astonished at how huge it was. We found three types of tubers: one that looked like a sweet potato, was about 10 inches long (we think these are the older tubers); another that was round and reddish (we think these are the newer tubers) and the many round purple tubers which are the crowns for next year’s plants. These crown tubers weighed in at 11 lbs. We will store these in sand and replant next year. As for the other two plants: one we cut the stalks down and covered with barn straw and we will be experimenting whether we can harvest a few tubers through the winter. The other one we left the stalks on and also covered the base with barn straw.
We cut the stalks down.
The tuber mass weighting in at 33 lbs (contains 22 lbs. of edible tubers and 11 lbs. of crown tubers).
Happy Master Gardener Charlene with our entire yield from one plant).
We found the Yacón to be moist, sweet with a hint of strawberry or melon, and with a texture very much like jicama. The flavor is very good. After Yacón is harvested, it should be left out to increase the sweetness. We left ours on our kitchen counters for a few days. The skin can be either scrubbed off or pealed. Yacón remains low in calories. This is due to the fact that the sugar contains high levels of oligofructose (inulin) a form of sugar that is not metabolized readily by the human body. For this reason, Yacón shows much promise as a food for diabetics and as a base for a low-calorie sweetener. Yacón is high in fiber, low in fat, and rich in inulin. Some consider it to be the super food of the future.
Next year, we will plant the crown divisions in growing medium in 4-6 inch pots, two/three months before the last frost date. The resulting plants will be hardened off and transplanted only after the soil warms and all danger of frost has passed. We will allow at least a three-foot diameter for each plant to grow. One problem which other gardeners have had is gophers; one gardener reported seeing the entire plant being dragged into the ground. At Elkus Ranch we have gopher-proof beds.
Virginia’s Yacón recipes:
Yacón in Salad:
Sliced up in an ordinary green salad with ordinary dressing was a great hit.
Thai Yacón Salad
1 median Yacon, shredded
1 carrot, shredded
1 tomato, quartered
¼ cup roasted peanuts
½ cup lime juice
1/3 cup fish sauce
Sugar to taste
Mix all together, yum.
Thai Chicken
(serves 2)
½ can coconut milk
½ “Taste of Thai Panang Curry Base”
¼ lb chicken breast, cut up in pieces
1 tsp lemon juice
1 med tomato quartered
½ bell pepper (any color)
2 scallions or onions
1 cup mushrooms, sliced
1 cup Yacón cut in one-inch pieces
Cook all ingredients, except chicken, for ½ hour; then add chicken and cook 15 min longer. Serve w/ rice.
The San Mateo/San Francisco Master Gardeners’ YacónTrial was a great learning experience and we are glad to be able to share what we learned with the home gardeners of our community. The plants are easy to grow, just watch out for gophers. The tubers are very delicious and we would like to encourage home gardeners to try this unusual crop.