Black beans are a popular crop grown primarily for their dried seeds. Whether these plants require vertical support depends entirely on the specific growth habit of the chosen variety. Understanding the difference between the two main types will clarify the cultivation approach and prevent potential issues during the growing season.
Identifying Black Bean Growth Habits
Black beans are categorized into two primary growth types: determinate and indeterminate. Determinate varieties, commonly known as bush beans, grow to a fixed, compact height, typically between 1 and 2 feet tall, forming a self-supporting shrub-like shape. Their growth is concentrated, and they produce most of their pods in a concentrated period, making them ideal for a single, large harvest.
Indeterminate varieties, known as vining or pole beans, produce long, twining stems that continue to grow and flower throughout the season. These plants can reach heights exceeding six feet and produce beans over a much longer harvest window. Since their flexible stems lack structural rigidity, indeterminate types require an external support system, while determinate types are cultivated without one.
Cultivation Requirements for Bush Varieties
Bush black beans are favored in gardens with limited space because of their compact size. These varieties are typically planted four to six inches apart in rows that are 18 to 24 inches apart. The planting site should feature well-draining, moderately fertile soil with a slightly acidic pH, ideally between 6.0 and 6.5.
A sunny location that receives at least six hours of direct sunlight each day is necessary for optimal production. Bush beans focus their energy on a synchronized production cycle, resulting in an earlier and more uniform yield. While they are generally self-supporting, a light, low-lying support, such as short bamboo stakes, can prevent heavily laden plants from sprawling onto the soil surface. Watering should be consistent until the plants flower, after which it should be reduced as the pods begin to yellow and dry.
Establishing Support for Vining Black Beans
For indeterminate black bean varieties, providing a robust vertical structure is necessary to manage their vigorous climbing habit. Vertical growth keeps the foliage and developing bean pods elevated, which significantly improves air circulation. Better airflow reduces humidity and minimizes the risk of fungal diseases, such as powdery mildew or rust. Growing vertically also simplifies locating and picking the beans during the prolonged harvest period.
The support structure should be installed at the time of planting to prevent damage to the delicate root systems later in the season. Common trellising methods include:
- A-frames, which provide a stable, freestanding structure.
- Bamboo teepees, effective for growing multiple plants in a compact area.
- Net trellises, made from durable materials like nylon or jute, stretched between two posts.
- Cattle panels arched between two raised beds for very tall varieties.
Harvesting and Curing
Black beans are typically grown as a dry bean crop, meaning the seeds must fully mature and dry inside their pods on the plant. The pods should be left on the vine until they turn yellow or straw-colored, feel dry and brittle to the touch, and the seeds inside are hard and completely black. This drying phase usually takes between 90 and 140 days after planting, depending on the variety and local growing conditions. If rain is expected before the pods are fully dry, the entire plant can be cut at the base and hung upside down in a sheltered, well-ventilated area to finish the drying process.
Once the pods are thoroughly dried, the beans are shelled out and need a final curing stage before they are ready for long-term storage. The shelled beans should be spread out in a single layer on a screen or tray in a cool, dry location for about one to two weeks to ensure any remaining moisture is removed. Moisture can lead to mold growth and spoilage. The fully dried beans can then be transferred to an airtight container and stored in a cool, dark place, where they will maintain their quality for up to a year.