Long Bean Trial 2007

Nine Palms Ranch Trial, 2008

Lead: Karen Schaffer
Team members: Jean Lee, Ken Lee, plus assistance from many Nine Palms regulars

Summary

We compared 12 varieties of long beans, Vigna unguiculata, to determine which ones have the best production and the best flavor for growing here in Santa Clara County. Chinese Green Noodle was the most productive variety by far, and was the favorite in the first tasting for its very tender, mild pods. Chinese Red Noodle was a favorite for those who like beans with a richer flavor and a firmer texture, and was a good producer.

Soil preparation

The plot had previously been used for a raspberry trial. In May we finished removing the raspberries and rototilled in four inches of compost.

Arbor

We created an arbor structure for the beans to climb by bending 16-foot lengths of five-foot wide concrete reinforcing wire into an arch and lashing them to eight-foot posts that had been driven one and one-half feet into the ground. The arch is 4 feet wide, 7 feet high in the center, and 35 feet long. The one-foot wide planting beds are mounded slightly, about six inches higher than the center of the pathway. The concrete reinforcing wire has a 6-inch mesh.

The bean arbor in May, 35’ long, 4’ wide, 7’ high

On August 10

Seeding and transplanting

We planted the beans directly into the ground on June 1, two beans per hole, six inches apart, and thinned them after two weeks to one seedling every six inches. There were eight vines of each variety, four vines on each side of the arbor so they could grow up to the center and meet. There was a one-foot gap between varieties.

The planting order was the same on both sides of the arbor. We attempted to alternate the pod colors for ease of harvesting, although the pod colors weren't known for all varieties. From south to north (front to back), it was:

Taiwan Black (light green)
Chinese Mosaic (lavender-pink)
Black Stripe Seed (light green)
Chinese Red Noodle (deep red)
Thai Red Seeded (green)
Canton White Pod (light green)
Kaoshiung (dark green)
Red Stripe Seed (light green)
White Seed (light green)
Surinam Asparagus Bean (green)
Red-Seeded Asparagus Bean (deep red)
Chinese Green Noodle (bright green)

Watering

Irrigation was set to 45 minutes, three times a week.

Fertilization and pesticides

No additional fertilizer was used. No pesticides were used.

Harvesting and observations

Harvesting began on August 7 with Chinese Mosaic and Chinese Green Noodle. Our last harvest was September 28, and the vines were removed on October 2. The biggest producer, by far, was Chinese Green Noodle, followed by Chinese Mosaic and Chinese Red Noodle.

Clusters of Chinese Mosaic long beans

Long beans mature quickly and need to be picked every few days so they don’t become overmature and tough. In general, they should be picked while still slender, before they get puffy and the seeds become visible. Thai Red Seeded and White Seed were two varieties that could be allowed to get a little fatter and meatier than the others while still remaining tender.

We harvested through Sept 28, although at that point most varieties were producing a few ounces or less. Only Canton White Pod (10 oz) and Thai Red Seeded (13 oz) were still producing more than minimal amounts that final day.

Variety Total
production
in ounces
First
harvest
Last
harvest
Pod
color
Description Source
Black Stripe Seed 23.5 4-Sep 28-Sep Light green Very branching at bottom, vigorous growth Evergreen
Canton White Pod 58.5 4-Sep 28-Sep Light green Lighter green leaves, short beans Evergreen
Chinese Green Noodle 212.5 7-Aug 28-Sep Bright green Vigorous growth, big producer Baker Creek Heirloom Seeds
Chinese Mosaic 135.5 7-Aug 21-Sep Lavender-pink Early production on lower branching vines Baker Creek Heirloom Seeds
Chinese Red Noodle 134.5 24-Aug 25-Sep Deep red Vigorous, dark green leaves Baker Creek Heirloom Seeds
Kaoshiung 0.5 28-Sep 28-Sep Dark green Short vines, never really produced, mosaic virus Evergreen
Red Stripe Seed 44.5 31-Aug 28-Sep Light green Signs of mosaic virus Evergreen
Red-Seeded Asparagus Bean 82.5 21-Aug 28-Sep Deep red Short and concentrated production Baker Creek Heirloom Seeds
Surinam Asparagus Bean 58 24-Aug 28-Sep Green Curly beans Baker Creek Heirloom Seeds
Taiwan Black 84.25 24-Aug 28-Sep Light green Very long beans Baker Creek Heirloom Seeds
Thai Red Seeded 82.75 21-Aug 28-Sep Green Very vigorous vines and dense foliage Baker Creek Heirloom Seeds
White Seed 62.25 28-Aug 28-Sep Light green Lighter green leaves, signs of mosaic virus Evergreen

All 11 varieties that produced, on 9/7/07

Tasting

We conducted two tastings. The first one was on Aug 24 with the five varieties that were producing at the time (Chinese Green Noodle, Chinese Mosaic, Chinese Red Noodle, Red-Seeded Asparagus, and Thai Red-Seeded). The second tasting was on September 18, with all varieties except Kaoshiung, which only produced one pod at the very end. For both events, Jean individually stir-fried samples of each of the varieties in a hot wok with oil, a little salt, and some water to steam. People were welcome to taste the beans raw as well, if they wanted to.

Variety First tasting votes Second tasting votes Comments
Black Stripe Seed None to taste 11 Sweeter than others
Canton White Pod None to taste 3 Nice flavor
Chinese Green Noodle 11 0 Very tender, mild, good taste. Very similar to the long bean widely available in San Francisco Chinatown, perhaps due to its high yield. (For second tasting, this variety was past its prime.)
Chinese Mosaic 1 2 Turns dark green when cooked, nutty flavor, firmer texture, not sweet
Chinese Red Noodle 7 4 Rich, deep flavors, chewy. But some people disliked the firmer texture, calling it tough.
Kaoshiung None to taste None to taste  
Red Stripe Seed None to taste 6 Deep flavor, meaty, lingering flavor
Red-Seeded Asparagus Bean 6 3 Almost as tender as Green Noodle, crisp, nutty
Surinam Asparagus Bean None to taste 5 Asparagus-like flavor when raw, grassy, a little tough
Taiwan Black None to taste 0 A touch bitter, grassy, not meaty, tender after cooking
Thai Red Seeded 0 2 Heavy flavor, not as sweet as others, very tasty, sweet, meaty. Can be picked at a larger diameter, resulting in sweeter, meatier beans.
White Seed None to taste 1 Very sweet, meaty if allowed to develop, very tender

Pests & diseases

Ants were present on the vines and flowers. They did not appear to be causing any damage, but were merely visiting the extrafloral nectaries present on the flowers.

Red Stripe Seed, White Seed, and Kaoshiung varieties showed signs of bean mosaic virus from the start, so I suspect the seed was infected. We didn’t do anything, although in retrospect perhaps we should have taken out the infected vines so the virus wouldn’t be spread to any others. We didn’t save seed from any of the varieties due to the presence of the virus in the plot.

Long bean flower with ants

Bean mosaic virus

Conclusion

Chinese Green Noodle was the most productive variety by far, and was the favorite in the first tasting for its very tender, mild pods. Chinese Red Noodle was a favorite for those who like beans with a richer flavor and a firmer texture, and was a good producer. Black Stripe Seed was rated highly for flavor but was a poor producer.