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!

Thursday, November 8, 2012

Odontonema strictum (Firespike)

Odontonema strictum is a great shrub for late summer through early winter blooms. The red tubular flowers attract hummingbirds and butterflies.
Also known as firespike or cardinal's guard, this plant grows 3-5 feet tall in full sun to half shade. Blooms appear in clusters at the tips of the stems and the inflorescence continues to elongate throughout the flowering period.
Often, the flower spike will take on a crested form as the season progresses.
Firespike is classified as an herbaceous perennial, since it doesn't form woody stems. The broad green leaves are about 6 inches long, and deer are known to feed on the lush foliage.
Odontonema strictum is native to Central America and is recommended for USDA Zones 8-11. Frost will damage the foliage, but the plants quickly re-sprout from remaining green stems, or from the crown of the plant at soil level.
Plants are very drought-tolerant once established, but thrive in evenly moist soils.
O. strictum is considered to be synonymous with O. cuspidatum.

Related reading: Odontonema callistachyum

Thursday, October 25, 2012

Carica papaya

Carica papaya is a fast growing tropical herb that produces delicious fruit. Many different strains exist, producing fruit sizes ranging from 1 to 20 pounds. The flesh color also varies from plant to plant and may be yellow, orange or reddish.

Papaya grows rapidly. Under ideal conditions flowers and fruit will be produced the first year from seed, often starting when the plant is only 4-5 feet tall. It takes 3-4 months from flower to mature fruit.

When the skin is mostly yellow it's time to pick the fruit, cut it open, and enjoy! Even the black seeds are edible and have a peppery taste similar to nasturtium.

Mature green fruits may be cooked as a vegetable. A young plant will produce 2-3 ripe fruits per week. Older, branched plants will produce many more.
Leaves are palmate and deeply lobed, often growing more than 2 feet across. In the East Indies, young leaves are cooked and eaten like spinach. Crushed leaves wrapped around a tough cut of meat before cooking will help tenderize it. The milky latex exuded by immature fruits is also collected and used in commercial meat tenderizers.
Old plants form thick trunks that support a branching canopy of foliage. Branching is often stimulated by some injury to the growing tip, such as a light freeze. This 10-year old papaya has a trunk circumference of 4.5 feet at the base.

Carica papaya has a complex sexual morphology. Plants may be male, female or hermaphrodites. All flowers are very fragrant.
female flower
male flower


Papaya is believed to have originated in Central America, but is now cultivated in tropical regions around the world. They are recommended for USDA Zones 10-11, but due to their rapid maturity, can be successfully grown in Zone 9 as well. I have had several plants live more than a decade in my Zone 9B garden. Most references indicate that productivity rapidly declines with age, but I find older, branched specimens produce far more fruit than young, single-trunk plants.

Thursday, October 11, 2012

Podranea ricasoliana

Podranea ricasoliana is a vigorous vining plant that blooms throughout the warm months of the year, when the plant is actively growing. The pink flowers appear in clusters on the ends of new growth. Each flower is about 2 inches across and lightly fragrant. Unfortunately the fragrance doesn't travel, so you'll have to stick your nose right into the bloom to catch the scent. There are about 18-20 flowers per cluster, opening several at a time.
Although this is a vining plant, the stems do not twine, grasp, or root onto their supports. Instead, the long flexible stems head skyward and simply lean or lay across supporting objects, which are often adjacent trees or shrubs. It quickly and easily climbs to 30 feet or more. When stems reach the top of a tree they arch over, and either flower or head back to the ground and form another plant.
If no vertical objects are nearby to climb, the stems run across the soil surface until they find a place to climb. Wherever stems contact the soil, they'll send out roots and start a new plant so it's imperative to keep horizontal shoots clipped off. Old plants develop a woody trunk that is deeply furrowed with a corky texture.
Leaves are dark green, pinnate, opposite on the stem, and 6-8 inches in length.
It's unclear where Podranea originated, but it is common in tropical and subtropical regions around the world. The plant will grow in nearly any location, surviving heat, drought, and several degrees of frost. Flowering is best in full sun. It is recommended for USDA Zones 9-11, but may survive as a perennial in slightly colder locations.
Common names include pink trumpet vine and Port St. Johns creeper.

Tuesday, September 18, 2012

Doritis pulcherrima

One of the most reliable orchids for late summer and fall blooms is Doritis pulcherrima. Even the smallest plants rarely fail to send up a spike each year.
This genus is closely related to Phalaenopsis and much hybridization between the two has been done over the years. The Doritis genes bring smaller plant size and a more erect flower spike to their progeny.
The natural species usually only has a leaf spread of 4-6 inches and several plants can grow comfortably together in a 4-inch pot.
They multiply by clumping so it's typical to see plants grouped together in a single pot. When they fill the pot it's time to divide them, giving each one its own space. I like to divide in the spring, giving the young plants all summer to get established and ready for the annual bloom.
Individual flowers are about 3/4 inch across, with petals strongly recurved back toward the stem. The blooms open a few at a time, progressing up the spike, which continues to elongate as new buds are produced. The flowering period easily lasts for 2-3 months, with the spikes often reaching 3 feet in height. In high light the spikes are mostly vertical, but in shade they tend to bend toward the light.
Doritis pulcherrima is a fairly cold-tolerant species and survives brief temperatures in the upper 20°F range if situated under dense trees or shrubs during cold snaps. It also tolerates higher light and drier conditions than its Phalaenopsis relatives.

Friday, September 14, 2012

Turnera ulmifolia

Turnera ulmifolia (TERN-er-uh  ul-miff-FOLE-lee-uh) is an ever-blooming shrub that thrives in subtropical gardens. The bright yellow flowers each last only a day, but new flowers are continuously produced. The plant grows about 3 feet tall in a single season and requires very little care. It is drought-tolerant and thrives in nearly all soil types. The dark green leaves are usually about 2-4 inches in length and the flowers are about 2 inches in diameter.

Turnera ulmifolia is sometimes called yellow alder, but it is not an alder so that is a poor choice for a common name. There's really no reason to call it anything other than Turnera. It is native to the Caribbean and is recommended for USDA Zones 9-11. A hard freeze may knock it back to ground level, but it will quickly recover when the weather warms. In colder locations it can be grown as an annual. The plant reseeds itself easily and you're likely to find seedlings coming up all around the garden. The seedlings are easily identified by the distinctive leaf, so they can be pulled, transplanted, or allowed to remain where they sprout, depending on your preference.
Although you may find seedlings coming up in random locations, they generally aren't prolific enough to become weedy. The flowers attract butterflies, especially Gulf Fritillaries and Sulphurs.

Thursday, August 9, 2012

Cuban Oregano (Plectranthus amboinicus)

Plectranthus amboinicus is a tender perennial herb with many common names including Cuban oregano, Spanish thyme, oregano brujo, broadleaf thyme and big thyme.
The leaves are chopped and used with stuffing, salads and meats. It can also be used as a substitute for oregano or sage. If you've picked a few leaves for use in the kitchen and didn't use them all, do not refrigerate what's left. This is a tropical herb and refrigerator temperatures quickly cause brown deteriorating spots. Excess leaves store very well in a sealed plastic baggie or container at room temperature for up to two weeks.
The leaves are large, fleshy and covered with fine hairs.
In full sun the leaves are generally 3-4 inches in diameter, but with a little shade they can easily reach 6" or more in length. Long stems tend to flop over, so keep the plant compact by frequent harvest of the growing tips for use in the kitchen.

This plant is recommended for USDA Zones 9B-11. In areas that experience frost, Cuban oregano is best grown as an annual during the warm months. In frost-free areas the plant is perennial, developing a woody stem at the base and growing about 2 feet in height.
Older plants are not as vigorous, so I like to plant fresh starts each spring that quickly become large specimens. Cuban oregano thrives in sun or part shade. There is also a variegated form that is slower-growing.

Saturday, August 4, 2012

Alpinia galanga

Alpinia galanga is the spice that is most frequently used in Thai food. While it is botanically known as a ginger, and is even sometimes known as Thai ginger, for culinary purposes it is referred to as galangal. The flavor is more peppery when compared to ginger root.

The older, tan-colored rhizomes have the most intense flavor, while the new tender sections are milder. If you often flavor your cooking with ginger, this species is a good one to grow because the rhizomes may be dug at any time of the year for use in your favorite recipes. Unopened flower buds are also edible when steamed. 

The large inflorescence of greenish-white flowers is very showy for a short period of time in mid-summer. The canes are evergreen when grown in frost-free locations, and flowers will appear at the tops of the previous year's growth.

The erect canes grow 4-6 feet tall and individual leaves are 2-3 inches wide by 12-14 inches long.
Although they will grow in sun or shade, the plants perform best in moist environments. I had a clump growing for years in a part of the garden with no irrigation. It survived, but barely produced enough rhizomes to keep the clump going, much less have any for harvest. Since I moved the clump to an area that receives over-spray from the nursery irrigation I now have to harvest the rhizomes on a regular basis to keep the clump a manageable size.
Alpinia galanga is recommended for USDA Zones 8B to11.
Use it in curry pastes, stir-fries, soups and tea. Most cooks peel galangal before use. The rhizome is very dense and requires a longer cooking time than ginger, so it is usually cut in thin strips or crushed before being added to a recipe.

The rhizomes have been used in folk medicines to treat a wide range of ailments. It has strong anti-oxidant and anti-inflammatory properties.

Wednesday, July 11, 2012

Alpinia calcarata

Sometimes called Snap ginger, Alpinia calcarata is a very easy evergreen species that blooms on old growth. Blooms can occur at nearly any time of the year, but peak flowering occurs from late spring to early summer. The inflorescence is carried upright on the end of the cane. Leaves are long and narrow, about 1 to 2 inches wide by 14 inches long.
The thin-stemmed canes arch gracefully from the weight of leaves and flowers. The inflorescence always grows erect, regardless of the degree of arch in the cane.
The clumps grow 3-4 feet in height and spread wider as they multiply. Rubbing or bruising the foliage releases a pleasantly spicy fragrance.
Rhizomes are thin with well-spaced canes.
Alpinia calcarata is recommended for USDA Zones 9-11. It is native to India and grows in sun or shade.
The rhizome is not considered edible, but experimentally, rhizomes of Alpinia calcarata are shown to possess antibacterial, antifungal, anthelmintic, antinociceptive, anti-inflammatory, antioxidant, aphrodisiac, gastroprotective, and antidiabetic activities.

Buy Alpinia calcarata rhizomes

Saturday, July 7, 2012

Alpinia nutans

Among the many types of gingers, Alpinia nutans is one that is grown primarily as a foliage plant because it supposedly rarely flowers in cultivation. It may just need the right cultural conditions. As you can see, the flowers are beautiful and it's one of the earliest gingers to bloom in spring. The erect inflorescence contrasts nicely with the dark green foliage.
The flower spikes appear on the ends of mature canes, so don't cut down the foliage in winter or you won't get blooms. 
Unopened buds are soft pink...
and pop open to reveal the vivid red and yellow lip.
This plant is sometimes sold as Dwarf Cardamom or False Cardamom. The foliage has a very pleasant cardamom scent when bruised, but this is not the species that produces the spice called cardamom.
The broad-leafed evergreen canes grow 3-5 feet tall and individual leaves grow about 3½ inches wide by 15 inches long. The canes crowd together in a dense clump and can live for years if not damaged by cold.
Alpinia nutans is recommended for USDA Zones 8-11. In Zone 8 the canes may freeze to the ground in the winter, then send up new growth in the spring. The foliage looks its best when grown in shade to part-sun locations.