I want to share some thoughts about adding Perennial Tuber and Root Vegetables to your garden. I planted a number of varieties in the Fall of 2012 and spring of 2013. It takes a full season or two for many of these to become established enough that you can begin to dig and eat the root crops. Last fall I got a taste of a couple (Ground Nut and Chinese Artichoke). This fall I was pleased to try them all. I am continuing to dig and cook with them, atleast until the ground freezes. All in all, they are easily grown, but there has been a few problems along the way, namely, my failure to follow growing instructions. I am now finding that my ill prepared beds have crowding issues as well as an incursion of perennial weeds. This is what inevitably happens when I rush into any project. I am currently in the process of moving each perennial root crop out of their current congested beds and into new spaces around the farm. They will no longer grow in wide 4′ beds, but rather in single rows of deeply prepared soil. Each crop will have it’s own area surrounded by easily mowed grass walkways. This should help to contain them from sprawling and spreading where I don’t want them. I am still desiring to work with a polyculture design for some, but this is going to take time to figure out which make the best companions as well as solving the perennial weed issues. With all that said, let me give a brief update on each of these wonderful crops.
SKIRRET Last fall I dug one plant and was very disappointed. I expected the roots to be small, but was frustrated to find all of them to have a woody core. This fall I dug three more plants. What a difference a year makes. All the roots were tender and free of any woody core. The flavor is somewhat like a parsnip. They sweeten up after frost and are excellent raw, boiled or roasted. Each plant was a large mass of 5”-8” long roots. Skirret prefers moist to wet soils and will readily self seed if you don’t remove the seed heads before they mature. Two thumbs up for this forgotten, “Old World” crop!!
CHINESE ARTICHOKES This perennial tuber vegetable that will give you a nice crop in one season. They are extremely easy to dig and propagate. The only trick is to harvest the majority of little tubers each fall and only leave a few to regrow. If you don’t, overcrowding will reduce the yield and size of next years harvest. They are small and a little time consuming to dig but absolutely delicious. The mild flavored, white, curly tubers can be cooked, but I think they are best eaten fresh as a snack or in salads. If they are to be cooked, something like a stirfry would be preferable, for maintaining their delightfully crunchy texture. Chinese Artichokes work great as an edible ground cover since they grow only 12”-16” tall and smother out all competing weeds.
GROUNDNUT An amazing perennial, native to many parts of the United States. This tuber is thought to have been served at the original Thanksgiving dinner. Extremely easy to harvest, as the edible tubers grow laterally only inches below the soil. They prefer moist soil and will readily spread underground, if not properly contained. The vines are sprawling and need something to climb on. I provide a bamboo teepee for each plant. In the future I plan to try naturalizing them in some low ground, where it stays fairly wet, next to the perimiter of our woods. They are delicious, with a intense “earthy” flavor and starchy texture. I have boiled them, as well as roasting them with onions and garlic. I prefer them roasted as their natural sugars carmelize in the cooking process.
EARTH PEA These little 1”-2” long tubers grow under beautiful perennial pea vines, with pinkish-red flowers. They need 2 yrs to size up and are very easy to dig. The flavor is delicious, earthy and sweet (and very starchy). They can be boiled or roasted. Roasting seems to be the best option, as the tubers natural sugars carmelize under the heat, the flavor becomes more intense. Some folks describe the flavor akin to a “sweet chestnut”. The only problem with Earth Pea is that they can become invasive. It spreads like mint and should be contained. A 12” root barrier is advisable. I am replanting mine into a space that is surrounded by grass pathways which I will keep mowed. This plant would work great to stabalize a slope or hill to reduce erosion.
CHINESE and JAPANESE YAMS Also known as “Wild Mountain Yam”. These are, in my estimation, the best of the bunch. Possibly one of the most unusual root crops I have ever grown. The 2 yr old tubers are good sized (1/2-1 lb.) with short, hairy roots covering the thin, pale skin. When you cut one open, things get weirdly interesting. The white flesh is sticky and mucilaginous, and a little strange to handle. Once baked though, it fluffs up like dry, flaky potato, only moister and a little sweet. Absolutely superb with a dab of butter. Wild mountain yam is also excellent when roasted with a drizzle of olive oil. While mostly unknown here, in Japan, the mountain yam or “jinenjo”, is widely consumed. Known to be nutritious and considered a “medicinal food”, with “strengthening” properties. In ancient Japan, women were forbidden to eat jinenjo for fear they would become to masculine. Today in Japan, it is commonly eaten raw as “tororo”. I have not yet tried this, but plan to in the near future. The only difficulty with growing wild mountain yam is digging the roots. Chinese yams grow straight down (2 year old plants can produce roots over 2 feet in length) and can be very difficult to remove without breaking or damaging the tuber. The Japanese variety grows more like a sweet potato and produce lateral tubers (usually more than one). This makes digging a little easier and you can leave one tuber in the ground, so the plant will continue growing for the next season. Next year I am planning to build a tall and narrow raised bed, specifically for these yams. I would like to make the sides of the bed removable to make harvesting the long, delicate roots easier.
Overall I think all 5 of these deserve a place in any garden. Great plants for the serious permaculturist and all around good fun for any gardener/cook, at any skill level. I am glad to have an abundance of these in my own “sufficency garden” plan. All 5 survived the brutally cold winter of 2013/14, without a single lost plant. I will be offering them as potted plants and cutting in the spring and fall. I may have a few available as seed this winter.