Snap Beans

History

Snap beans are legumes and members of the Fabaceae family, also known as the pea family, which includes other warm season beans, peas, lentils, and peanuts, along with many other plants, shrubs, and trees (see Figure 1).

This crop is thought to have originated in the Latin American countries of southern Mexico, Guatemala, Honduras, and Costa Rica. Snap beans thrive in these sandy clay soils and have been grown in Mexico for over 7,000 years. However, there is evidence that snap beans may have been cultivated much earlier in Peru, as seeds were found with a mummified woman buried with pre-Incan artifacts. Native Americans introduced snap beans to North America prior to European colonization and transported this crop through Mexico and into the southwestern U.S. By 1492 snap beans were found in Florida and spread up the East Coast to Virginia. In the 16^th century, Spanish explorers introduced this crop to Europe, and trading continued its migration. See Figure 2.

The original varieties of snap beans were called “string beans” due to the fibrous string lining the pods, visible when snapped. By 1890 breeding programs in the U.S. began to produce the modern stringless varieties. By the 1950s, the majority of snap beans produced were stringless and resistant to the common bean mosaic virus. The French are credited with the culinary presentation of snap beans in restaurants and are famous for their thin and flavorful green bean variety: Haricot Vert (pronounced arr-ee-co-vair).

Snap beans were originally grown for their seeds, but today the entire pod is edible. This is contrary to shell beans, like the Lima bean (a different species, Phaseolus lunatus), which are grown for the seed rather than the edible pod. Pole snap beans require support, as plants grow over eight feet tall. Historically, Native Americans planted this crop beside corn, using the corn stalks as natural support for bean plants, while squash covered the ground to prevent weeds. Hence, the native companion growing method is called “Three Sisters” (see Figure 3).

Today, snap beans are distributed all over the world and are especially popular in the southern U.S. during Thanksgiving, baked into a green bean casserole. There are over 100 varieties of snap beans, varying in shape, size, and color. They are one of the most commonly grown vegetables in American gardens.

Varieties

There are two main types of snap beans, both annuals, differing chiefly in their growing habit and plant size: (1) bush bean and (2) pole bean. Both types are fairly cold and heat sensitive, although pole beans are more heat tolerant and will produce further into the summer.

Bush beans are short and, as the name suggests, they have a bush growth habit. Bush beans are determinate, meaning they generally set fruit at the same time during a shorter harvest period, as stem growth stops at a “determined” height with a terminal bud (see Figure 4). Bush snap bean varieties may differ in color, size, flavor, and disease/pest resistance. These include traditional green beans with round and straight pods (e.g., Blue Lake, Contender, and Provider); giant, green Italian Romano varieties (e.g., Jumbo and Roma II); slender and buttery French Haricot Vert varieties (e.g., Maxibel); and yellow wax beans (e.g., Gold Rush and Golden Wax).

Pole beans are indeterminate, meaning they have a stem that continues to grow “indeterminately,” producing fruit progressively over a longer harvest period (see Figure 4). Bush beans do not require support, unlike pole beans, which grow to over eight feet tall and need to be supported by stakes or trellises. Varieties of pole beans also differ in appearance and disease/pest resistance, with traditional green and round varieties (e.g., Blue Lake, Kentucky Blue, and McCaslan); colorful and striped varieties (e.g., Louisiana Purple and Rattlesnake); and the flat Romano variety called Northeaster. The Yardlong Asparagus Bean is a vigorous and more heat tolerant pole bean variety producing pods over two feet long, and closely related to the southern pea.

Almost all snap bean varieties are open-pollinated (including heirloom). Some snap beans are heirloom varieties, like Cherokee Wax and Tendergreen bush beans and the rattlesnake pole bean, meaning the seeds have been saved for at least 50 years and can be saved each season and replanted. Bean flowers are perfect (containing both male and female parts) in both types of snap beans. All snap beans are self-pollinating, so if saving seed, different varieties need to be separated by a distance of 10-20 feet to prevent cross-pollination.

It is recommended to select disease-resistant varieties when possible. See the recommended snap bean varieties for Louisiana in Table 1.

Table 1. Recommended Snap Bean Varieties for Louisiana

When and How to Plant

While snap beans are warm season crops, they can also be successfully planted in the fall (refer to the Snap Bean Planting Guide, Table 2, for recommended dates). Snap beans should be direct seeded outside, ideally when soil temperatures are between 60-85 degrees F. In the spring, seeds can be planted with the soil temperature warms to 60-65 degrees F and, in the fall, when the soil temperature cools to 85 degrees F. Seed germination is very poor below 50 degrees F and above 95 degrees F. The use of a soil temperature map can help guide planting decisions.

Bush snap beans can be planted intensively, as plants are smaller, allowing for two rows of seeds planted 18 inches apart in each raised row (see Table 2). Plant seeds 1-inch deep and spaced 2-4 inches apart, cover with soil, and water in. Seeds should germinate in 7-14 days.

Pole snap beans need support for vines, such as stakes, a fence, or a trellis at least 6-8 feet tall. Another option is building a “tepee” out of poles (use this video as a guide). If using a fence or trellis for support, sow 2-4 seeds every 6 inches in single rows (see Table 2). If using the “tepee” method or stakes for support, place stakes or set poles every 12 inches and then sow 5-7 seeds around the tepee (see Table 2). Plant seeds 1 inch deep, cover with soil, and water in. Seeds should germinate in 7-14 days.

After germination, snap beans prefer warm days (80-85 degrees F) and cool nights (55-60 degrees F). Avoid growing past the end of May or in temperatures over 90 degrees F as this will cause bloom drop, along with poor pollination and fruit set. For a continuous supply of snap beans, sow seeds outside every 2 weeks during the recommended planting dates.

Table 2. SNAP BEANS PLANTING GUIDE

Where to Plant

Snap beans should be sown into well-drained soil with a pH between 5.5 to 6.8 that receives full sun (at least 6 hours/day). Avoid soils that crust easily as this prohibits germination; snap beans grow best in sandy, clay soils. It is recommended to plant snap beans in box beds or in traditional raised garden rows that are 8-10 inches tall to ensure good drainage. It is recommended to add a layer of compost, peat moss, rotted hay, or other organic matter and mix into the soil to optimize plant health.

Each season, rotate plant families — avoid planting crops from the same plant family in the same area of the garden — to reduce disease and pests. A crop rotation of at least 2 years is recommended for legumes like snap beans to reduce risk of root rot disease.

Plant Care

Watering

Snap beans should be watered weekly (1-1.5 inches), being sure to maintain soil moisture during blossom and pod set stages. Drip irrigation is preferred to reduce diseases. If watering overhead, irrigate in the morning when the sun can dry plant leaves quickly.

Fertilization

Beans, a member of the legume family, can interact with soil microorganisms to gather nitrogen from the air into specialized nodules on the plant root system. This makes them a “light feeder” of nitrogen. Do not overfertilize, as excessive nitrogen will induce plants to remain in a juvenile, vining stage that delays flowering and fruiting.

Organic fertilizers such as compost, fish emulsion, composted poultry litter or manure, worm castings, and blood or bone meal originate from living organisms. They are far more environmentally sustainable and safe than traditional synthetic fertilizers. They naturally release nutrients more slowly and over a longer period of time. When applying organic fertilizer, it is important to use in unison with compost, cover crops, and crop rotation, which all work together to build soil health. Learn how to convert inorganic fertilizer recommendations to organic fertilizers here.

Alternatively, a synthetic fertilizer may be used at a rate of about 1/2 pound (1 cup) of 13-13-13 for every 25 feet of row or 75 square feet. Broadcast, or sprinkle evenly, over the soil and then mix in about 3-6 inches using a rake. For long-growing pole beans, supplemental sidedressing, or reapplication of synthetic fertilizer, may be applied after the first beans appear. Sidedressing is the addition of fertilizer to the soil around already established plants when the plant begins to fruit or vine, primarily to provide nitrogen. When using synthetic fertilizer, sprinkle lightly down the sides of the row; water into the soil. Additional sidedressing may be applied every 3-4 weeks, especially for pole beans. Because of their slow, steady release of nitrogen, crops fertilized with organic fertilizer do not need to be sidedressed.

Weeds

Early weed control is important for this fast-growing crop to avoid decreased yield and quality. Snap bean roots are shallow, so weeding by hand is recommended. Organic mulch is useful for weed control, but plastic mulch is not recommended for bush beans due to the close spacing of bean plants.

Insect Pests and Diseases

Common insect pests for snap beans are aphids, whiteflies, spider mites, and thrips. Snap beans are susceptible to diseases such as anthracnose, blight, bean mosaic virus, bean rust, downy and powdery mildew, and root rot. Many varieties of snap beans are resistant to specific diseases and these should be selected and planted. Other recommended tools for prevention are crop rotation, weed control, and good sanitation practices. See Table 3 to aid in diagnosis and management of some common snap bean insect pests and diseases.

Table 3. ORGANIC AND NATURAL MANAGEMENT FOR COMMON SNAP BEAN INSECT PESTS AND DISEASES

Harvest and Storage

It is recommended to harvest snap beans in early maturity before the beans become tough. By hand, harvest bush snap beans 2-3 times every few days, and pole snap beans 7-10 times on a 5- to 7-day schedule. When harvesting, be sure to pick all mature (and overmature) beans to promote a healthy and productive plant. Take care not to break branches and stems.

Harvested snap beans should be stored in a plastic bag, unwashed, in the refrigerator. In ideal storage conditions of 40-45 degrees F (with 95% humidity), snap beans will last 7-10 days.

Snap beans may be preserved by canning, freezing, or drying.

Snap Beans are Nutritious and Good for You

Good source of dietary fiber

Important for bowel health, lowering cholesterol, controlling blood sugar, and maintaining a healthy weight

High in Potassium

Essential for body function, especially the heart, kidney, nerves, bones, and muscles

Rich in Vitamin C and A

Important for bones, skin, blood vessels, eye health, a strong immune system, and cell growth

Recipes

Common methods of cooking and recipes snap beans

Video showing how to prepare snap beans

Taste-testing ideas: snap bean and tuna salad, green bean casserole, three-bean salad, Louisiana green beans (with peppers, onions, tomatoes), stir fry, Southern green beans with bacon

Other websites with many snap bean recipes:

USDA MyPlate Kitchen

Food Hero

SNAP-Ed Arizona

Produce for Better Health Foundation

Sources

• Southeastern Vegetable Extension Workers, 2020 Southeastern U.S. Vegetable Crop Handbook
• LSU AgCenter, Louisiana Vegetable Planting Guide
• LSU AgCenter, Louisiana Commercial Vegetable Production Recommendations
• LSU AgCenter, Vegetable Gardening Tips: Beans
• UF Extension, Planting Guide
• UF Extension, Vegetable Production Handbook of Florida
• Texas A&M AgriLife Extension, Vegetable Varieties for Central Texas
• Texas A&M AgriLife Extension, Easy Gardening: Green Beans
• Texas A&M AgriLife Extension, Commercial Crop Guides: Beans: Green/Snap
• Alabama A&M and Auburn Universities Extension, Common Diseases of Snap and Lima Beans
• UMass Extension Vegetable Program: Beans, Snap, Dry, and Lima Fact Sheet
• UMass Extension Vegetable Program: Disease, Insect, and Mites Fact
• PennState Extension, Snap Bean Production
• University of Arizona CALS: Green Beans
• Purdue Extension FoodLink: Snap Bean
• Maynard, Donald N & Hochmuth, George J (2007). Knott’s Handbook for Vegetable Growers (5th edition). John Wiley & Sons, Inc.
• Decoteau, Dennis R (2000). Vegetable Crops. Prentice-Hall, Inc.
• Swiader, John M & Ware, George W (2002). Producing Vegetable Crops (5th edition). Interstate Publishers, Inc.
• Sukprakarn, S, Juntakool, S, Huang, R, and Kalb, T (2005). Saving your own vegetable seeds—a guide for farmers. AVRDC publication number 05-647. AVRDC—The World Vegetable Center, Shanhua, Taiwan. 25 pp.
• Seed Savers Exchange, A Guide to Isolation Distances
• University of Georgia Extension, How to Convert an Inorganic Fertilizer Recommendation to an Organic One, Circular 853