Jicama (Pachyrhizus tuberosus)

Jicama (Pachyrhizus tuberosus) is tropical vining legume that forms a large edible root. The vines climb by twining and can reach a length of 20-30 feet, given sufficient support. The trifoliate leaves are opposite on the stem and can be up to 18 inches across. As a legume, this plant is capable of nitrogen fixation and therefore has low fertilizer requirements.

Flower buds start to appear in the leaf axils by late summer.

These quickly open into bright blue pea-like blossoms as the inflorescence elongates.

For maximum root production you should clip off the flower buds as they form so all the plant's energy goes into the storage root, rather than seed production. The root continues to increase in size as long as the vine is green and growing, so a long growing season is also beneficial for maximum production. Note that all parts of the jicama plant should be considered poisonous except the root, even though stems and leaves are used as animal forage in some regions.

Each pollinated flower develops into a bean-like pod.

The pods grow to about 5-6 inches in length over a 2-3 month period, turning dark brown or black as they reach maturity.

When they have fully dried, the pods split open to release the seeds.

By this time the vines have also started to dry and decline and you can dig the edible root. Each vine produces a single, sometimes lobed, storage root, which varies in size and shape. Roots can become quite large, often weighing several pounds, but smaller ones are much more common.

They have a thin tan skin and a crisp white or sometimes yellow interior, depending on the cultivar. Jicama may be eaten either raw or cooked, and they retain their firm crunchy texture even after cooking.

Peel and slice the root in salads, soups and stir-fries or serve with fruits. Cut into sticks and use with your favorite dips. Jicama is a very good source of vitamin C and also a good source of potassium. The root contains oligofructose inulin, which is a sweet inert carbohydrate that is not metabolized by the human body, so is a good sweet snack for dieters and diabetics. Oligofructose is also prebiotic.

Harvested roots should be stored in a cool dry location, but not refrigerated.

Pachyrhizus tuberosus is native to Central America, but is cultivated in tropical and sub-tropical regions around the world. The closely-related P. erosus is similar except with a smaller root and is the species more frequently grown on a commercial scale.
Technically, jicama is a perennial in USDA Zones 10-12 and a new vine will sprout from unharvested roots, but it is normally grown as an annual and harvested after the first growing season. I've been more successful growing a new crop from seed each year, rather than letting the old roots sprout again. A harvest can be obtained anywhere with a growing season of at least 5 months.

Propagation is by seed. Soak the seed in water overnight before planting. Any seeds that don't show signs of swelling can be nicked with the edge of a sharp knife and soaked for a few more hours. Keep the seedbed warm and moist. Germination should occur within 2-3 weeks.

Yacon (Smallanthus sonchifolius)

Yacon (Smallanthus sonchifolius) is a perennial root crop that tastes like a fruit. People in the Andes region of South America have cultivated and enjoyed it for more than a thousand years. Only now are scientists discovering its many health benefits, and commercially-produced yacon syrup is becoming widely available.

It grows multiple stems 6 feet or more in length from a densely-clustered rhizome. When they get too tall they tend to lean over and curve upright again. Stems touching the soil are able to root and start a new growing point, and new shoots may sprout from the rhizome.

The large fuzzy leaves grow opposite on the stem and can reach more than a foot in length. They have a distinctive winged petiole.

Yacon leaves may be used to wrap food when cooking, or dried and made into a tea. The leaves and stems are cooked like a vegetable, but I find they have a somewhat unpleasant resinous tang.

Yacon is in the Asteraceae family and in late summer small sunflower-like blooms appear on the tops of the stems.

It is during this time that yacon starts to grow its storage roots -- the most prized part of the plant. As the autumn days get shorter and cooler, the foliage starts to decline and the roots increase in size. The rhizomes also multiply rapidly during this time and start to push up out of the soil.

In frost-free regions, dormancy may be induced by the onset of the dry season.

I allow the plant to go completely dormant and then carefully dig around the clump and lift it up. Several of the thick storage roots will be radiating out from the clump of rhizomes. These are easily snapped off for eating, and the rhizomes can be set back in the ground or divided and replanted in multiple locations. Roots average around half a pound each, but reportedly can weigh up to 5 pounds.

The first year I grew this crop, I started with about a dozen rhizome pieces smaller than my thumb. From that, I harvested about 7 pounds of edible root. I expect I will get a much larger harvest the second year when starting with much larger rhizomes.

Yacon root is sweet, juicy and crunchy with a pleasant apple/pear/watermelon flavor and texture. When first dug, the skin is very thin and pale. As the roots are exposed to the air over a few hours or days, the skin becomes much darker.

The thin skin is generally scraped off before eating, but I find that to be an unnecessary step for freshly dug roots because the pale skin doesn't seem to affect the flavor in any way. The darker skin of cured or dried roots may impart a resinous flavor. Yacon root may also be steamed or baked, but I prefer them raw. The rhizomes are also edible, and have the same flavor as the root.

The sugar level in the root increases over time while in storage, but since I let the plants go completely dormant before digging, I can't detect any difference in sweetness between fresh-dug and cured roots. In climates with a shorter growing season, where the crop is dug at first frost, I would imagine there is a more pronounced difference in taste.

Yacon is native to the Andes mountains of South America and is cultivated from sea level up to 9000 feet. It is recommended for USDA Zones 7-11. It will grow in full sun or part shade, and produces best with a steady supply of moisture. The plants rarely set viable seed, but are easily propagated by division of the rhizome or by stem cuttings.

I like to eat yacon simply for the flavor and texture, but its sudden popularity is no doubt due to its medical benefits:
Weight loss and blood sugar: A study published in 2009 in "Clinical Nutrition" concluded that "Yacon syrup is a good source of fructooligosaccharides and its long-term consumption produced beneficial health effects on obese pre-menopausal women with insulin resistance. Daily intake of yacon syrup produced a significant decrease in body weight, waist circumference and body mass index."

Cancer prevention:  "Food and Chemical Toxicology" published a study in 2012 finding that "yacon
and yacon plus Lactobacillus casei intake may reduce the development of chemically-induced colon cancer." Other studies have found similar results on other types of cancer cells.

Prebiotic:  The "Journal of Agricultural and Food Chemistry" published a study in 2003 proposing "yacon fructooligosaccharides as a potential novel source of prebiotics."

Antioxidant:  In 1999, the  "Journal of Agricultural and Food Chemistry" published a study identifying two major antioxidants in yacon root.

These are just a few of the many studies confirming a wide variety of healthful benefits from eating yacon. What benefits have you experienced from yacon?

Winged yam, Ñame (Dioscorea alata)

Dioscorea alata is commonly known as winged yam, water yam, white yam and ñame.
The species name alata means winged and refers to the flattened edges of the squarish stems.

This is one of the true yams that are tropical in origin. Yams are twining vines that quickly climb to the top of any available support. They can completely cover nearby trees or shrubs with leaves that are arrow-shaped and 6-8 inches in length. They are arranged opposite each other on the stem. There are other similar-appearing species with poisonous tubers so make sure you're able to properly identify the edible ones if you're going foraging.

While the plant is in active growth it will put out aerial tubers at many of the leaf joints. These aerial tubers are edible, but generally not considered as good for eating as the underground tuber. They're also considerably smaller and, pound for pound, require a lot more effort to peel and cook. The aerial tubers are, however, ideal propagating material for starting new plants.

They'll grow where they fall on the ground or you can plant them in new locations for additional yam production the next year. They sprout readily, and in some regions this is considered an invasive species. The bumps on the tuber become roots when in contact with soil. Here you can see a fallen tuber taking root:

During the growing season the edible tuber increases in size until the vine goes dormant in late fall or winter. At this time the yam tuber is dug and consumed. Tubers left in the ground will sprout again in the spring and increase in size the following year. Yams grown from aerial tubers will usually produce 1-3 pounds of edible tuber the first year, but over a few years time they can achieve a weight of over 100 pounds.
Here's a nice 3-pounder from my garden:

The mature yams are peeled and then baked or boiled until tender. When raw, the cut surfaces have a very slimy texture, but this disappears when cooked. There are many cultivated varieties with different shapes and sizes of tubers, and also some with white, yellow or purple flesh. The purple yam is commonly known as Ube.

Dioscorea alata is believed to be native to Southeast Asia, but has been cultivated in tropical Africa for over 2000 years. From there it was brought to North America on slave ships as early as the 17th century. Its cultivation was encouraged due to its edibility and ease of growth. It is now distributed throughout tropical regions around the world.

Winged yams grow best in sun or light shade, and flourish in moist soils. It has naturalized throughout much of USDA Zones 9 and 10 in the Southeastern U.S. Some locations list it as an invasive species.

White turmeric (Curcuma zedoaria)

Curcuma zedoaria is very similar in appearance to golden turmeric, although somewhat smaller-growing and not quite as prolific. The primary visual difference is that the rhizomes are white instead of the yellow-orange color of turmeric.

This species is also known as white turmeric or zedoary, although herbalists often sell several different species under the name zedoary. Sometimes they will differentiate between "long zedoary" and "round zedoary" based on the shape of the rhizomes of the different species. Apparently they have similar medicinal uses, which may explain part of the naming confusion. There was also much confusion among early plant collectors and their plant descriptions. I base my identification of this species on a scientific paper titled "Taxonomic and nomenclatural puzzles in Indian Curcuma". It's probably only worth a look if you have a background in botany or taxonomy!

The leaves are broad and thin-textured, reaching 2 to 3 feet in height. Plants are in active growth during the warm months and go dormant as the days shorten in late fall and early winter. Growth resumes by mid-spring.

The rhizomes can be dug anytime the plants are dormant. Break off the "fingers" for use in the kitchen and replant the main rhizome for next year's crop. To me it tastes something like a strong-flavored carrot-parsnip blend with a peppery aftertaste. I like it grated in a salad or finely chopped into mixed vegetables or stir-fries. It's frequently added to pickled vegetables or curries.

Zedoary is used medicinally to treat inflammation, anxiety, stress, and fatigue according to WebMD, although there has been little scientific research done on this plant. Pregnant or breast-feeding women are advised not to take this supplement. Zedoary may also be applied directly to the skin as a mosquito repellent.

Curcuma zedoaria is native to Southeast Asia. It grows well in USDA Zones 8-10 and can be grown as a container plant in colder locations.

Also see: Curcuma longa

Golden turmeric (Curcuma longa)

Curcuma longa, commonly known as turmeric or Indian saffron, is a ginger relative that has long been used to add flavor and color to food. It also has medicinal applications, and is used to treat arthritis, heartburn, stomach pain, headache, colds, fever, depression, Alzheimers, and liver problems, all according to the doctors at WebMD.

As a garden or landscape plant, turmeric thrives in tropical and sub-tropical regions. Turmeric leaves are broad with heavy parallel venation and thin texture.

The foliage is light green and reaches about 3-4 feet in height over the course of the growing season. Turmeric grows best when it gets plenty of moisture throughout the growing season, and will tolerate sun or light shade.

Late in the year, the foliage declines as the plants go dormant. Now is the time to dig your harvest. Rhizomes branch freely as they grow, making a large mass close around the stem of the plant. Lift the entire clump and spray it with a strong jet of water to expose the golden wonder of turmeric.

You can break off the rhizome "fingers" for use in the kitchen. Grate fresh turmeric into chutney, pickles, meats, vegetables, rice and salad dressings. The flavor gets stronger as it's cooked so use it sparingly until you're familiar with the results. Turmeric tea is another easy way to get the health benefits of this amazing plant. It can also be used as a dye, so be aware that it will stain just about anything it touches a bright yellow color!
During the growing season, turmeric leaves can be used to wrap and cook food.

Turmeric stores best in the ground, so only dig it as you need it through the winter. I usually dig up a whole clump, break off what I need immediately, and "plant" the rest of the clump in a pot of mulch or compost. This makes it easy to retrieve fresh turmeric whenever I want it without digging up more clumps. It may also be stored in a sealed container in the refrigerator.

Extra rhizomes may be dried and ground to a powder for use during the summer months when the plants are in active growth.

Replant the mother stem with a portion of rhizome to grow again next year. Turmeric can also be propagated by planting some of the individual fingers just under the soil surface. When temperatures warm in the spring, growth will resume.

Curcuma longa is native to Southeast Asia and is recommended for USDA Zones 7b to 10b, but can be container-grown in colder climates.

See also Curcuma zedoaria

Ginger root (Zingiber officinale)

Ginger root (Zingiber officinale) has been one of the most widely used spices since ancient times. It has a variety of documented health benefits and is easy to grow as well.
The ginger "root" is actually a thick rhizome that grows right at the soil line and supports upright canes of leafy green foliage. The canes get 3-4 feet tall and the leaves are long and narrow, giving a bed of ginger a grassy appearance.

A long growing season is required to get a good harvest, and commercial ginger farms are usually in tropical regions with regular rainfall throughout the growing season.
Ginger can also be grown in containers, but the yield will generally not be as great as plants grown in the ground.
Late in the growth cycle, flower buds emerge from the rhizome and reach about 8 inches in height above the soil line. Small cream-colored flowers with a reddish-brown lip emerge from the bracts of the flower bud a few at a time over a period of a few weeks. Each flower is only open for a few hours in the morning, and the inflorescence is often hidden by the foliage.

The rhizomes continue to increase in size and weight during the growing season. In the top photo you can see the progression in the size of the rhizome as it grows from left to right.
Late in the year the swelling rhizomes may even push up out of the soil as they grow. The ginger may be harvested at this stage and is sometimes marketed as "baby ginger". Because it is more tender and less fibrous, this is the stage in development used for pickled and candied ginger.

In late fall, the canes wither and dry up as the plants go dormant.  At this time the mature ginger is ready to harvest. Since the rhizomes are very near the surface, they are easy to dig. In loose soils, you can just brush away the dirt from the top of the rhizome and gently dig it up with a trowel or small shovel. Store it in a cool dry place until ready to use. Rhizomes left in the ground will sprout again in the spring and have a larger yield the following year. If you dig more than you can use immediately, you can freeze the excess harvest for later use.

Note that fresh ginger is light in color with only a thin skin, as seen in the top photo. It does not have the thick brown peel usually found on dried and imported ginger root, even though imported ginger is often marketed as "fresh". Newly harvested rhizome only needs a light scrubbing to make it ready for the kitchen, while dry imported ginger will have a tough fibrous skin that needs to be peeled before use.

Ginger root is used in the kitchen to flavor tea, cookies, cakes, and many other sweet or savory dishes. The fresh leaves can also be chopped and added to soups or stews for a milder ginger flavor.
Medicinally, ginger is used to treat nausea, headache, muscle and joint pain, and arthritis.

Zingiber officinale is native to Southeast Asia and is recommended for USDA Zones 8-12. It is propagated by planting pieces of the rhizome about 1 inch deep at the start of the growing season.

Sweet lemon (Citrus limetta)

Sweet lemon (Citrus limetta) is an acid-free or low-acid variety of citrus. The same species is also sometimes known as sweet lime.

On the outside they are a typical lemon-yellow color. The flesh inside is pale yellow-green to nearly colorless.

They taste like a very mild lemon, without the acid bite.They are popular in Asia and the Middle-East, but somewhat difficult to find in the U.S. If you see them in a local market, buy some and try them.

Sweet lemon sections can be eaten whole, like an orange. They can also be juiced and drank plain or diluted with ice water for a refreshing beverage.
Sweet lemon trees grow similar in size and shape to other lemons, reaching about 12 feet tall and wide.

Like other citrus, the trunks and branches have long thorns.

Flowering occurs in the early spring with typical, highly fragrant citrus blossoms.

The fruit grows to about 3 inches in diameter and starts to ripen in late fall. The harvest continues throughout the winter. They are very prolific, but mature fruits hold well on the tree for several months so you only need to pick them as you need them.

Citrus limetta is native to Southeast Asia, and will grow in just about any region where other citrus trees are grown. This is approximately USDA Zones 9-11.

Schefflera arboricola

Schefflera arboricola (shef-LEER-uh ar-bor-ih-KOLE-uh) is a widely-grown houseplant that is also a durable landscape plant in tropical and sub-tropical regions. It is sometimes known as dwarf schefflera or Hawaiian schefflera. The palmately-compound leaves are glossy and dark green, with a diameter of about 6-8 inches.

Stems are thick and sturdy. On lower portions of the plant they often send out aerial roots that thicken after reaching the soil to become prop roots.

Plants can grow up to 15 feet tall and wide, but are easily trimmed to any size or shape desired. In late summer there are greenish, almost inconspicuous flowers on the ends of the branches.

These develop into round berries that turn a showy orange-red in the fall, giving the plant great seasonal appeal.

Schefflera arboricola is native to Southeast Asia and is very drought-tolerant once established.
It is recommended for USDA Zones 9B to 11, in exposures ranging from full sun to deep shade,
and can be grown anywhere as a container plant or houseplant. This species is easily propagated by stem cuttings or seeds.
There are many different cultivars available including this one with variegated leaves.

Cassava, Yuca (Manihot esculenta)

Manihot esculenta, also known as cassava, yuca and manioc, is a fast-growing perennial with an edible tuberous root. In common usage, the plants are usually referred to as cassava and the roots are marketed as yuca. This may vary depending on locality. The roots are the source of the starch that is processed into tapioca.

Plants quickly grow to a height of about 10-12 feet and then flop over if not topped. Trimmings can be chopped and composted, or spread as a weed-suppressing mulch between plants. Stems can reach 20 feet or more in length if allowed to sprawl.

Cassava is grown world-wide in tropical regions, but originated in Central and South America. There is archaeological evidence that it has been in cultivation for at least 4,000 years and possibly as long as 9,000 years.
The leaves are palmate, about 8-10 inches across, and deeply lobed. Some cultivars have red petioles, making a nice contrast to the dark green leaves.

Older stems have a distinctive prominent stub where each leaf was attached.

Plants put in the ground in spring grow throughout the summer and flower in autumn. The cream-colored flowers appear in clusters at the ends of the branches, but they are small, and go almost unnoticed amid the foliage. Only close inspection reveals their beauty.

After about 9-10 months of growth the yuca roots are large enough to harvest. Roots that are 3-4 inches in diameter and 10-15 inches long are a harvestable size. Production volume doubles if harvest is put off until after the second vegetative cycle, but the roots are supposedly not as tender.
When grown commercially, the entire plant is dug, roots are harvested, and a new crop is planted the following spring or at the start of the rainy season. If you only have one or two plants, it's possible to dig around the base of the plant, harvest the mature roots, and leave the plant to produce another year. I've been doing that for years on the plant pictured below.

The one root at the top of this grouping weighed over 6 pounds. I'd only dug out half of the root system when this photo was taken, so you see they can be quite productive.

Yuca roots are prepared by peeling, then cooking in the same manner as potatoes; boil, bake, roast, or fry them. They must be cooked before eating due to cyanic compounds present in the raw roots. The heat from cooking renders these compounds inert. Some cultivars with very low levels of cyanide can be eaten raw, but you'd have to be certain you had that cultivar and bitterness is not necessarily an indication of cyanide levels.

The grated root is used for cassava bread, and young leaves are also edible after cooking. To prepare the leaves, remove the petioles, then finely chop, grind or pound the leaves. Cook them as greens, seasoned to your own liking, or add to soups and stews. I like to puree the leaves in the blender, cook and season them, and serve over rice or pasta. There are lots of recipes available online. 

**Cassava leaf must be cooked thoroughly before eating! Cassava leaf is a good source of vitamin A, C, B vitamins, iron, calcium, zinc, manganese and magnesium.

There is a variegated form of cassava that is primarily grown as an ornamental. It doesn't produce the large roots of the commercial varieties, but makes a showy addition to any landscape.

To start a new crop, mature cassava stems are cut into sections and laid horizontal in a shallow trench, then covered with soil. Alternately, the may be simply poked straight down into the dirt, with a few nodes visible above the soil line. In commercial plantings they are spaced about 4 feet on center. The cuttings produce an abundance of roots and quickly start growing. I have cassava plants and cuttings for sale -- click the link at the bottom of this post.

Cassava tolerates a wide range of soils and environmental conditions, making it an ideal crop for impoverished soils and drought-prone regions. In some parts of the world, cassava is grown as livestock feed or as a biofuel.
Manihot esculenta is recommended for USDA Zones 8-11. It can be grown in colder climates as an annual ornamental, but the growing season won't be long enough to produce a good crop of roots.
Buy cassava cuttings.