Sunday, November 25, 2012

Sunchoke (Helianthus tuberosus)

Helianthus tuberosus is a species of sunflower that produces edible tubers commonly referred to as sunchokes. The plants grow 6-10 feet tall, depending on variety, and are covered with bright yellow sunflower blooms all summer long. The flowers are about 3 inches in diameter and lightly fragrant. Each plant sends up multiple stems that generally remain unbranched until flowers start to form.
In the fall, as the days shorten and become cooler, the plants decline and turn brown. In short-season growing areas, frost may be the determining factor for the end of growth.

Once the plants are dry and brittle, it's time to dig the tubers. Most of the edible portions will be within 12-18 inches of the main stem and within 8 inches of the soil surface. I dig a circular perimeter around the plant and then work toward the center excavating the tubers. In sandy soils I do most of the digging with my hands. It's easier to find small tubers this way. In heavier soils a shovel or potato fork works well.

Watch my video on digging sunchokes here

It seems that sandy soil also produces knobbier tubers, while heavy soils produce smoother, more compact tubers. The photo above shows tubers dug from heavy, mucky soil, while the photo below shows the same variety grown in almost pure sand.
Here is a photo of some tubers grown in compost:
The harvest will consist of tubers ranging in size from tiny pips to pieces weighing a couple of ounces. The total yield per plant averages 2-4 pounds in typical garden conditions, although yields as high as 6-10 pounds have been reported for commercial plantings. Any pieces you miss while digging will remain dormant over the winter and then grow new plants as the soil warms in the spring.
A few named varieties exist that have been selected for skin color, yield, or tuber shape. Some have reddish skin and some have more torpedo-shaped tubers.

The harvested sunchokes should be stored in the refrigerator in a sealed container, where they'll keep for several weeks. If they become dehydrated they'll feel rubbery, but they'll firm up again when soaked in water.
After they are washed and lightly scrubbed, sunchoke tubers can be eaten either raw or cooked. The raw tubers have a sweet, crisp quality like jicama or water chestnuts, and are excellent alone or thinly sliced in salads. They can be added to stir-fries, soups and stews. They can also be cooked like potatoes.
Nutritionally, sunchokes are a very good source of iron, and a good source of thiamin, phosphorus and potassium. The carbohydrates in the tuber are stored as inulin, which breaks down into fructose rather than glucose during digestion. For diabetics, this makes it a good substitute for other starchy foods like potatoes.

Helianthus tuberosus is an annual, only living for one season, but the buried tubers that re-sprout in the spring give it a perennial growth habit. It is recommended for USDA Zones 3-9.

The species is native to the eastern half of North America, and many Native American tribes consumed the tubers which they called sun root. They are also known as topinambour. In some regions, the plants and tubers are mysteriously known by the misleading and nonsensical name of Jerusalem artichokes, even though there is absolutely no connection to either Jerusalem or artichokes!


sharon said...

Inever knew they had a flower...I would like to grow them!

David The Good said...

We had great luck with these in TN, but haven't had much success here in Florida. I'm surprised to see you're growing them. This is the bottom of their range, for sure.

Gardens-In-The-Sand said...

Don't you have voles down there?
I'm growing my sunflower-taters in containers...
until I can figure out a solution to my rodent problems.

Grower Jim said...

Gardens in the sand, we have no voles here, but sometimes they do get dug up by something shortly after planting. They must not be all that appealing, because the dug-ups don't get eaten, they just lay there on top of the soil. I just bury them again and never have any more problems.

Anonymous said...

Many years ago, I grew them at our farm and loved them. However, I now live in a suburb and am wanting to grow them. I remember they can be invasive. At the farm, that wasn't a problem. However, here, I need to be careful. I've tried to find a diagram of how their root system grows to no avail. I've just now dug a 4x8' hole that is 3' deep. I bought a tree root liner and plan to put that around the inside perimeter of the hole. In your opinion, will that keep them at bay? I don't want them escaping all over the yard. Thanks for your help.

Grower Jim said...

There are running types and clumping types. Your method should keep the running varieties contained.