Cultivating green beans is a practice that requires some special attention, as the plant is quite delicate. In this article, we will explore how to grow them organically in our garden, avoiding common mistakes. To do this, we have decided to outline all the fundamental cultivation steps. These include: selecting the right variety, different sowing periods, setting up supports, and harvesting.
Another crucial aspect is the organic pest defense. Green beans are attractive to various harmful insect species. Therefore, it is essential to develop a preventive strategy that allows us to cultivate thriving green beans without using insecticides and phytosanitary products in general.
The Green Bean Plant
The green bean plant (Phaseolus vulgaris) is an annual herbaceous plant belonging to the Leguminosae family. This family also includes broad beans and peas.
The plant’s stem is erect and can be dwarf or climbing. The leaf structure usually consists of three small heart-shaped leaves with smooth edges. While the flowers are white, clustered in dense groups (from 4 to 10) in the leaf axils.
The flowering process is cleistogamous, meaning it occurs through self-pollination. While the fruit is a pendant legume with numerous seeds. The shape, color, and size vary depending on the variety. For example, they can be compressed or cylindrical, green or yellow, straight or curved, typically ranging from 6 to 20 cm in length.
Green beans are considered “siblings” of traditional beans but are distinct in nutritional properties and culinary uses. Unlike beans, which are grown for their fresh shelling seeds, we utilize the entire fruit of green beans without waiting for the seeds to mature.
Green Bean Varieties
Green beans – dwarf variety Slenderette
If you decide to grow green beans, you can choose from several varieties. There are two main categories.
The dwarf green beans do not grow too tall and are more suitable for intensive cultivation.
Then, there are the climbing green beans, which have robust vegetative vigor and a climbing growth habit of their branches.
These climbing varieties, as the name suggests, naturally twine around provided supports, climbing upwards.
Growing climbing green beans is recommended for home gardens as they offer abundant yields and a staggered harvest, which is convenient for personal consumption.
Here are some varieties (both dwarf and climbing) worth mentioning:
Dwarf Varieties
- Slenderette
- Fin de Bagnols
- Cropper Teepee plants, easy to grow, reach approximately 50 cm in height. They have an excellent yield. The pods range from dark green to light green, and they are straight and tubular, measuring from 15 to 18 cm in length.
Climbing Varieties
- Sofia, a widespread variety, with light green, flat pods that are 20 cm long or more, tender and stringless
- Marconi, widely cultivated, with light green, flattened pods that are 20 cm long or more
- Blue Lake, with white seeds. Straight pods, 15 cm long
How to Cultivate Green Beans: Sowing Period and Technique
Green beans require a minimum temperature of 10 degrees Celsius for germination. Therefore, it is advisable to sow them starting from the end of March. For flowering and maturation, this cultivation needs temperatures ranging between 20 and 30 degrees Celsius. Thus, sowing should not exceed the end of June. Excessively high temperatures could hinder fruit setting and make the pods tougher.
Green bean seeds are relatively large and germinate about 8-10 days after being sown in the ground. Unlike crops like tomatoes, it is preferable to sow them directly in the open field rather than using a seedbed. For organic cultivation, remember to always obtain organic seeds. Place 2 or 3 green bean seeds in small holes, approximately 4-5 cm deep, and spaced about 15-20 cm apart. The distance between rows varies from a minimum of 70 cm for dwarf varieties to one meter for climbing varieties.
Fertilization
Cultivating green beans does not require significant attention to fertilization or large amounts of organic matter. For this crop, manure fertilization can be avoided since it has a very short cycle. Moreover, being a leguminous species, the plant is nitrogen-fixing, meaning it can draw the necessary nitrogen from the soil for its vegetative growth, leaving the soil enriched with this essential element at the end of its cycle. For an ideal pre-sowing fertilization in the home garden, you can use the result of composting.
Irrigation
To cultivate thriving green beans, proper irrigation is necessary. It is required throughout the plant’s life cycle, particularly before flowering.
Using drip irrigation is ideal, so prepare a suitable irrigation system.
Ensure that the water supply is balanced, with the soil being moist but not overly wet. Avoid waterlogging to prevent root rot. On the other hand, excessively dry soil can lead to flower abortion or hardening of the fruits.
Supports for Vegetative Growth
Cultivating green beans with the support of bamboo trellis
Dwarf green beans do not require any support or tutor for their growth. These plants typically reach a height of around 50 cm and support themselves. However, they are less productive than climbing varieties.
Climbing green beans, on the other hand, need supports for their growth, as the plants can exceed two meters. In terms of yield, climbing varieties are much more satisfying.
There are two methods to create suitable supports for climbing green beans, both of which are valid and effective, so you can choose the one you prefer.
The first method involves crossing bamboo canes (illustrated in the first photo) to form a small hut-like structure around which the green bean plants grow. You can find these supports here.
The second method involves setting up wooden poles along the cultivation line. Approximately, a pole should be planted every two meters. To these poles, attach a plastic net on which the green bean plants can grow and develop both in height and width. For reliable supports with a good price-quality ratio, you can find them here. The choice depends on the available space in your garden.
Mulching
Keeping green bean plants free from weeds is essential. If you do not want to perform periodic weeding, it is best to use mulch. You can choose between natural mulch with straw, biodegradable plastic sheets, or jute mats.
Biological Pest Defense
Now, let’s move on to defending the plants from garden pests. This phase is crucial for cultivating healthy and thriving organic green beans. So, let’s proceed step by step. The main enemies of this crop are aphids and the red spider mite.
Aphids
Aphids tend to attack the undersides of leaves in small scattered groups. Over time, the infestation spreads, leading to a build-up of sticky honeydew on the foliage. An excellent remedy against this pest is to use a mixture of garlic macerate combined with pure Marseille soap. This combination serves a dual purpose: it repels the insects and cleans the plant from honeydew.
Red Spider Mite
The other arch-enemy of green beans is the red spider mite. This tiny mite, difficult to spot with the naked eye, appears on the plants during warmer periods, typically from May onwards.
Starting from the undersides of leaves, the red spider mite creates a dense, fine web that suffocates our green bean plants. The web hardens and damages the fruits, causing yellowing of the leaves, and in severe infestations, it can lead to the death of the crop.
Red spider mites thrive in dry and arid conditions. Cold water is an ideal solution to contain their spread, as it disrupts their reproductive cycle. With a backpack pump filled with cold water (you can add ice to the sprayer), give the affected vegetation a thorough and uniform wetting. Pay attention to spray the undersides of the leaves, where the mites nest. This easy, economical, and completely natural method will stop the development of the pest. Naturally, you should perform this operation during the cool evening hours to avoid subjecting the plants to excessive temperature stress. If you do not have a backpack pump, you can find one here.
Harvesting
Regarding harvesting, let me offer some recommendations. First of all, do not wait for your green beans to overripen; otherwise, they may become tough and start to produce seeds. Therefore, depending on the variety you have chosen to grow, harvest the fruits when they are well-formed but not overly mature.
Secondly, gently detach the pods from the plant, perhaps using your fingernails to assist. Green bean plants are delicate, and pulling the fruits too hard might break the plant or damage small beans growing alongside the ones to be harvested.
Nutritional Aspects
Cultivating green beans is ideal for those following a low-calorie diet. From a nutritional perspective, this food contains only 18 Kcal per 100 g. In contrast to beans, they have a low protein content, only 2 g per 100 g. Fats are almost non-existent, with only 0.1 g per 100 g.
Although the macronutrients (calories, proteins, and fats) are present in very small amounts, the same cannot be said for micronutrients. Green beans contain high amounts of vitamins A, C, and K and are a source of folic acid and some B-group vitamins. Regarding minerals, they contain excellent quantities of potassium, as well as calcium, phosphorus, and iron, which contributes to their health benefits for our bodies.
Further Reading
- University of Nebraska–Lincoln – “Green Beans – UNL Food” – A page dedicated to green beans, possibly containing information about their nutritional value and recipes.
- Oregon State University Extension – “It is time to get those green beans in the ground” – An article discussing the right time to plant green beans.
- Iowa State University Extension – “Some of my green beans got too large and bumpy. Are they still edible?” – A FAQ page addressing concerns about the edibility of large and bumpy green beans.
- Iowa State University Extension – “Yard and Garden: Growing Beans in the Home Garden” – An article providing guidance on growing beans, including green beans, in a home garden.
- Utah State University Extension – “Fruit and Vegetable Guide Series: Green Beans” – A guide to green beans, likely including nutritional information and preparation tips.
- Utah State University Extension – “How to Preserve Pole and Bush Beans” – An article on preserving various types of beans, including green beans.
- Oregon Agriculture in the Classroom – “Green Beans – Oregon Agriculture in the Classroom” – Information about the history and cultivation of green beans in Oregon.
- Wisconsin Department of Public Instruction – “Green Bean” – A fact sheet about green beans, possibly including nutritional facts and educational material.
- ArcGIS – “Green Bean Production in the United States – Overview” – An overview of green bean production in the United States, including where they are grown and how they are consumed.
